### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) and this hasn't been reported yet - [x] This is a single bug report (please file separate reports for different bugs) - [x] I am using the latest version of Claude Code ### What's Wrong? Cowork tab shows "Virtualization is not available" on Windows 10 Pro 22H2 (Build 19045.6466) despite Hyper-V being fully enabled and confirmed running. Lo

[BUG] Cowork HYPERVISOR_SERVICE_ERROR on Windows 10 Pro 22H2 — yukonSilver unsupported despite Hyper-V fully enabled

Resolved 💬 3 comments Opened Mar 26, 2026 by wcwells Closed Mar 30, 2026
Preflight Checklist

[x] I have searched existing issues and this hasn't been reported yet
[x] This is a single bug report (please file separate reports for different bugs)
[x] I am using the latest version of Claude Code
What's Wrong?

Cowork tab shows "Virtualization is not available" on Windows 10 Pro 22H2 (Build 19045.6466) despite Hyper-V being fully enabled and confirmed running. Log shows yukonSilver classified as unsupported, followed by HYPERVISOR_SERVICE_ERROR on every VM start attempt.
What Should Happen?

Cowork should detect that Hyper-V is active and initialize the VM successfully.
Error Messages/Logs

2026-03-22 19:16:00 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-23 10:57:04 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:10:39 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:14:22 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:15:24 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:16:14 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:19:05 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-26 12:23:26 [info] [Bundle:status] rootfs.vhdx missing
2026-03-26 12:23:26 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:23:26 [info] [VM] Module loaded successfully
2026-03-26 12:23:26 [info] [Bundle:status] rootfs.vhdx missing
2026-03-26 12:23:26 [info] [Bundle:status] rootfs.vhdx missing
2026-03-26 12:23:26 [info] [warm] No warm file found for rootfs.vhdx at current version
2026-03-26 12:23:26 [info] [cache] No cached compressed file for rootfs.vhdx
2026-03-26 12:23:26 [info] rootfs.vhdx not found, downloading...
2026-03-26 12:23:26 [info] Downloading rootfs.vhdx...
2026-03-26 12:23:33 [info] [KernelBugMonitor] State reset
2026-03-26 12:23:33 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:23:33 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:23:33 [info] [VM:start] VM instance ID: b0023ae9-ccc1-4f59-9a47-f342f358f2c3
2026-03-26 12:23:33 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:23:33 [info] [downloadVM] Download already in progress, waiting...
2026-03-26 12:24:08 [info] rootfs.vhdx.zst checksum validated
2026-03-26 12:24:08 [info] [downloadVM] Saved compressed rootfs.vhdx to cache
2026-03-26 12:24:08 [info] [Bundle:status] vmlinuz missing
2026-03-26 12:24:08 [info] [warm] No warm file found for vmlinuz at current version
2026-03-26 12:24:08 [info] [cache] No cached compressed file for vmlinuz
2026-03-26 12:24:08 [info] vmlinuz not found, downloading...
2026-03-26 12:24:08 [info] Downloading vmlinuz...
2026-03-26 12:24:08 [info] vmlinuz.zst checksum validated
2026-03-26 12:24:08 [info] [downloadVM] Saved compressed vmlinuz to cache
2026-03-26 12:24:08 [info] [Bundle:status] initrd missing
2026-03-26 12:24:08 [info] [warm] No warm file found for initrd at current version
2026-03-26 12:24:08 [info] [cache] No cached compressed file for initrd
2026-03-26 12:24:08 [info] initrd not found, downloading...
2026-03-26 12:24:08 [info] Downloading initrd...
2026-03-26 12:24:10 [info] initrd.zst checksum validated
2026-03-26 12:24:10 [info] [downloadVM] Saved compressed initrd to cache
2026-03-26 12:24:10 [info] All files ready in C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:24:10 [info] [VM:steps] download_and_sdk_prepare completed (37054ms)
2026-03-26 12:24:10 [info] [VM:steps] load_swift_api started
2026-03-26 12:24:10 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:24:10 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:24:10 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:24:10 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:24:10 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:24:10 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:24:15 [error] [VM:start] Startup failed: Error: VM service not running. The service failed to start.
    at wQe (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:21299)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async Object.configure (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:25727)
    at async gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:3786)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'VM service not running. The service failed to start.'
}
2026-03-26 12:24:15 [info] [VM:start] Auto-reinstalling workspace after startup failure
2026-03-26 12:24:15 [info] [deleteVMBundle] Deleting reinstall files from C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:24:15 [info] [deleteVMBundle] Reinstall files deleted (sessiondata.img and rootfs.img.zst preserved)
2026-03-26 12:24:15 [info] [VM:shutdown] App quit, stopping VM (instance: b0023ae9-ccc1-4f59-9a47-f342f358f2c3)...
2026-03-26 12:24:20 [error] [VM:shutdown] Failed: Error: VM service not running. The service failed to start.
    at wQe (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:21299)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async Object.stopVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:25961)
    at async Object.fn (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:2269)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:17228
    at async Promise.allSettled (index 13)
    at async zAr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:17107) {
  [stack]: [Getter/Setter],
  [message]: 'VM service not running. The service failed to start.'
}
2026-03-26 12:24:22 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:24:22 [info] [VM] Module loaded successfully
2026-03-26 12:24:27 [info] [KernelBugMonitor] State reset
2026-03-26 12:24:27 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:24:27 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:24:27 [info] [VM:start] VM instance ID: 31eeb5b6-ef75-4bc3-9e6b-7819775a4935
2026-03-26 12:24:27 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:24:27 [info] [VM:steps] download_and_sdk_prepare completed (4ms)
2026-03-26 12:24:27 [info] [VM:steps] load_swift_api started
2026-03-26 12:24:27 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:24:27 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:24:27 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:24:27 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:24:27 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:24:27 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:24:32 [error] [VM:start] Startup failed: Error: VM service not running. The service failed to start.
    at wQe (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:21299)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async Object.configure (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:25727)
    at async gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:3786)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'VM service not running. The service failed to start.'
}
2026-03-26 12:24:32 [info] [VM:start] Skipping auto-reinstall (already attempted once)
2026-03-26 12:26:59 [info] [stopVM] stopping VM gracefully
2026-03-26 12:27:04 [info] [deleteVMBundle] Deleting reinstall files from C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:27:04 [info] [deleteVMBundle] Reinstall files deleted (sessiondata.img and rootfs.img.zst preserved)
2026-03-26 12:27:04 [info] [VM:shutdown] App quit, stopping VM (instance: 31eeb5b6-ef75-4bc3-9e6b-7819775a4935)...
2026-03-26 12:27:09 [error] [VM:shutdown] Failed: Error: VM service not running. The service failed to start.
    at wQe (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:21299)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async Object.stopVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:25961)
    at async Object.fn (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:2269)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:17228
    at async Promise.allSettled (index 13)
    at async zAr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:17107) {
  [stack]: [Getter/Setter],
  [message]: 'VM service not running. The service failed to start.'
}
2026-03-26 12:27:11 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:27:11 [info] [VM] Module loaded successfully
2026-03-26 12:27:16 [info] [KernelBugMonitor] State reset
2026-03-26 12:27:16 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:27:16 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:27:16 [info] [VM:start] VM instance ID: 9a06669c-b855-4b58-8323-840b22dc30a7
2026-03-26 12:27:16 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:27:16 [info] [VM:steps] download_and_sdk_prepare completed (2ms)
2026-03-26 12:27:16 [info] [VM:steps] load_swift_api started
2026-03-26 12:27:16 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:27:16 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:27:16 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:27:16 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:27:16 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:27:16 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:27:21 [error] [VM:start] Startup failed: Error: VM service not running. The service failed to start.
    at wQe (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:21299)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async Object.configure (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:168:25727)
    at async gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:3786)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'VM service not running. The service failed to start.'
}
2026-03-26 12:27:21 [info] [VM:start] Skipping auto-reinstall (already attempted once)
2026-03-26 12:27:57 [info] [KernelBugMonitor] State reset
2026-03-26 12:27:57 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:27:57 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:27:57 [info] [VM:start] VM instance ID: 9a06669c-b855-4b58-8323-840b22dc30a7
2026-03-26 12:27:57 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:27:57 [info] [VM:steps] download_and_sdk_prepare completed (2ms)
2026-03-26 12:27:57 [info] [VM:steps] load_swift_api started
2026-03-26 12:27:57 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:27:57 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:27:58 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:27:58 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:27:58 [info] [VM:start] Windows VM service configured
2026-03-26 12:27:58 [info] [VM:steps] create_network started
2026-03-26 12:27:58 [info] [VM:steps] create_network completed (1ms)
2026-03-26 12:27:58 [info] [VM:steps] create_vm_config started
2026-03-26 12:28:01 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:28:01 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:28:01 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:28:01 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:28:01 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
2026-03-26 12:29:31 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:29:31 [info] [VM] Module loaded successfully
2026-03-26 12:29:31 [info] [KernelBugMonitor] State reset
2026-03-26 12:29:31 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:29:31 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:29:31 [info] [VM:start] VM instance ID: 8897b7f5-9e95-4778-8df0-f95759db3f51
2026-03-26 12:29:31 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:29:31 [info] [VM:steps] download_and_sdk_prepare completed (4ms)
2026-03-26 12:29:31 [info] [VM:steps] load_swift_api started
2026-03-26 12:29:31 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:29:31 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:29:31 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:29:31 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:29:31 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:29:31 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:29:31 [info] [VM:start] Windows VM service configured
2026-03-26 12:29:31 [info] [VM:steps] create_network started
2026-03-26 12:29:31 [info] [VM:steps] create_network completed (1ms)
2026-03-26 12:29:31 [info] [VM:steps] create_vm_config started
2026-03-26 12:29:35 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:29:35 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:29:35 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:29:35 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:29:35 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
2026-03-26 12:36:26 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:36:26 [info] [VM] Module loaded successfully
2026-03-26 12:41:25 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:41:25 [info] [VM] Module loaded successfully
2026-03-26 12:42:43 [info] [KernelBugMonitor] State reset
2026-03-26 12:42:43 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:42:43 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:42:43 [info] [VM:start] VM instance ID: 89bbd2e6-ba0d-42d9-b851-a513b7334955
2026-03-26 12:42:43 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:42:43 [info] [VM:steps] download_and_sdk_prepare completed (7ms)
2026-03-26 12:42:43 [info] [VM:steps] load_swift_api started
2026-03-26 12:42:43 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:42:43 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:42:43 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:42:43 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:42:43 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:42:43 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:42:43 [info] [VM:start] Windows VM service configured
2026-03-26 12:42:43 [info] [VM:steps] create_network started
2026-03-26 12:42:43 [info] [VM:steps] create_network completed (1ms)
2026-03-26 12:42:43 [info] [VM:steps] create_vm_config started
2026-03-26 12:42:46 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:42:46 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:42:46 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:42:46 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:42:46 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
2026-03-26 12:48:47 [info] [KernelBugMonitor] State reset
2026-03-26 12:48:47 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:48:47 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:48:47 [info] [VM:start] VM instance ID: 89bbd2e6-ba0d-42d9-b851-a513b7334955
2026-03-26 12:48:47 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:48:47 [info] [VM:steps] download_and_sdk_prepare completed (3ms)
2026-03-26 12:48:47 [info] [VM:steps] load_swift_api started
2026-03-26 12:48:47 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:48:47 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:48:47 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:48:47 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:48:48 [info] [VM:start] Windows VM service configured
2026-03-26 12:48:48 [info] [VM:steps] create_network started
2026-03-26 12:48:48 [info] [VM:steps] create_network completed (1ms)
2026-03-26 12:48:48 [info] [VM:steps] create_vm_config started
2026-03-26 12:48:48 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:48:48 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:48:48 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:48:48 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:48:48 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
2026-03-26 12:53:14 [info] [VM] Loading vmClient (TypeScript) module...
2026-03-26 12:53:14 [info] [VM] Module loaded successfully
2026-03-26 12:53:19 [info] [KernelBugMonitor] State reset
2026-03-26 12:53:19 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:53:19 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:53:19 [info] [VM:start] VM instance ID: dc6ef927-164f-4269-9f16-d05bdd4b74e8
2026-03-26 12:53:19 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:53:19 [info] [VM:steps] download_and_sdk_prepare completed (4ms)
2026-03-26 12:53:19 [info] [VM:steps] load_swift_api started
2026-03-26 12:53:19 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:53:19 [info] [Callbacks] Initializing VM event callbacks...
2026-03-26 12:53:19 [info] [Callbacks] VM event callbacks initialized
2026-03-26 12:53:19 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:53:19 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:53:19 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:53:19 [info] [VM:start] Windows VM service configured
2026-03-26 12:53:19 [info] [VM:steps] create_network started
2026-03-26 12:53:19 [info] [VM:steps] create_network completed (0ms)
2026-03-26 12:53:19 [info] [VM:steps] create_vm_config started
2026-03-26 12:53:19 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:53:19 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:53:19 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:53:19 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:53:19 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
2026-03-26 12:56:41 [info] [KernelBugMonitor] State reset
2026-03-26 12:56:41 [info] [VM:start] Beginning startup, bundlePath=C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-03-26 12:56:41 [info] [VM:start] Bundle version: fb30784dadb34104626c8cf6d8f90dd47cd393cc
2026-03-26 12:56:41 [info] [VM:start] VM instance ID: dc6ef927-164f-4269-9f16-d05bdd4b74e8
2026-03-26 12:56:41 [info] [VM:steps] download_and_sdk_prepare started
2026-03-26 12:56:41 [info] [VM:steps] download_and_sdk_prepare completed (3ms)
2026-03-26 12:56:41 [info] [VM:steps] load_swift_api started
2026-03-26 12:56:41 [info] [VM:steps] load_swift_api completed (0ms)
2026-03-26 12:56:41 [info] [VM:start] Copying smol-bin.x64.vhdx to bundle: C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\smol-bin.x64.vhdx -> C:\Users\W\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx
2026-03-26 12:56:41 [info] [VM:start] smol-bin.x64.vhdx copied successfully
2026-03-26 12:56:41 [info] [VM:start] Configuring Windows VM service...
2026-03-26 12:56:41 [info] [VM:start] Windows VM service configured
2026-03-26 12:56:41 [info] [VM:steps] create_network started
2026-03-26 12:56:41 [info] [VM:steps] create_network completed (0ms)
2026-03-26 12:56:41 [info] [VM:steps] create_vm_config started
2026-03-26 12:56:41 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host.","Provider":"17103e3f-3c6e-4677-bb17-3b267eb5be57","EventId":11008,"Data":[{"Type":"String","Value":"cowork-vm"},{"Type":"String","Value":"%%2151088386"},{"Type":"String","Value":"0x80370102"}]}]}
2026-03-26 12:56:41 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR
2026-03-26 12:56:41 [info] Dispatching startup error: HYPERVISOR_SERVICE_ERROR
2026-03-26 12:56:41 [error] [VM:start] Startup failed: Error: HYPERVISOR_SERVICE_ERROR
    at gYr (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:991:4545)
    at async Object.startVM (C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:7058:45197)
    at async C:\Program Files\WindowsApps\Claude_1.1.8629.0_x64__pzs8sxrjxfjjc\app\resources\app.asar\.vite\build\index.js:3:287074
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:116443) {
  [stack]: [Getter/Setter],
  [message]: 'HYPERVISOR_SERVICE_ERROR'
}
2026-03-26 12:56:41 [warn] [VM:start] Heartbeat restart failed, leaving VM offline (will retry on next app launch)
Steps to Reproduce

Windows 10 Pro 22H2 (Build 19045.6466), x64
Install Claude Desktop (direct .exe installer, v1.1.8629.0)
Enable Hyper-V, Virtual Machine Platform, Windows Hypervisor Platform via Windows Features
Set bcdedit /set hypervisorlaunchtype auto
Reboot
Open Claude Desktop and navigate to Cowork tab
Observe "Virtualization is not available" error
Claude Model

None
Is this a regression?

No, this never worked
Last Working Version

_No response_
Claude Code Version

1.1.8629.0
Platform

Anthropic API
Operating System

Windows
Terminal/Shell

PowerShell
Additional Information

System specs: AMD Ryzen 9 3950X, 128GB DDR4, Windows 10 Pro 22H2 (Build 19045.6466)
Verified working:
Hyper-V, Virtual Machine Platform, Windows Hypervisor Platform all enabled
bcdedit hypervisorlaunchtype set to Auto
CoworkVMService running (Automatic)
vmcompute service running
systeminfo shows: Hyper-V Requirements: VM Monitor Mode Extensions: Yes (single line = hypervisor IS running)
Tried both Microsoft Store (MSIX) and direct .exe installer
Log shows yukonSilver classified as unsupported on every launch, then HYPERVISOR_SERVICE_ERROR on VM boot attempts.
cowork_vm_node.log
View original on GitHub ↗
This issue has 3 comments on GitHub. Read the full discussion on GitHub ↗