[BUG] Claude Desktop reinstall fails with AddPackage HRESULT 0x80073CF9 (stuck CoworkVMService blocks removal)

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?

Claude Desktop crashed and had to be reinstalled. Reinstalling repeatedly fails with
"AddPackage failed: AddPackage failed with HRESULT 0x80073CF9". Setup logs show a
leftover CoworkVMService from the previous install can't be removed ("Access is denied"),
after which the installer falls back to an "in-place update" path that sometimes succeeds
and sometimes fails with the same error. This happened intermittently across two days
(2026/08/04, 2026/08/05), roughly 2 crashes/reinstall attempts a day.

What Should Happen?

Reinstalling should succeed cleanly without needing multiple manual retries or a full
uninstall. The installer should detect and clean up a stuck CoworkVMService/package
registration automatically instead of silently falling back to a path that isn't reliable.

Error Messages/Logs

[2026/08/04 13:30] WARNING: CoworkVMService already exists (potential conflict)

[2026/08/04 13:30] Removing: Claude_1.24012.11.0_x64__pzs8sxrjxfjjc

[2026/08/04 13:30] WARNING: Remove failed: RemovePackage failed with HRESULT 0x80073CFA

[2026/08/04 13:30] MSIX installation failed: AddPackage failed with HRESULT 0x80073CF9

[2026/08/04 13:31] ERROR dialog: Administrator access is required to install Claude with full features.

  You can try again or install without Cowork.

--- Retried 5 minutes later (no existing package left to remove) — succeeded ---

[2026/08/04 13:35] MSIX installation succeeded

--- Same day, later — another install trigger ---

[2026/08/04 15:09] WARNING: failed to remove conflicting service: could not open CoworkVMService: Access is denied.

[2026/08/04 15:09] Windows rejected data-preserving removal (0x80073CFA, requires developer mode);

  relying on in-place update

[2026/08/04 15:09] MSIX installation succeeded  (via the fallback path)

--- Next day, same pattern, but this time the fallback also failed ---

[2026/08/05 14:22] WARNING: failed to remove conflicting service: could not open CoworkVMService: Access is denied.

[2026/08/05 14:22] Windows rejected data-preserving removal; relying on in-place update

[2026/08/05 14:22] MSIX installation failed: AddPackage failed with HRESULT 0x80073CF9

Steps to Reproduce

1. Use Claude Desktop's Code tab for an extended session (Windows).
2. App crashes/closes unexpectedly.
3. Attempt to reinstall (via Start menu entry or downloading the installer fresh).
4. Installation fails with AddPackage HRESULT 0x80073CF9.
5. Log shows CoworkVMService could not be removed ("Access is denied") before the

AddPackage step.

1. Retrying sometimes succeeds after a few minutes, sometimes requires a full uninstall

first. Recurred on both 2026/08/04 and 2026/08/05.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A (Claude Desktop app) — Claude 1.26832.0 (056ee2) 2026-08-06T05:43:05.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Related issues with similar CoworkVMService/HRESULT mechanism: #49655, #49917, #56949, #47877

Separately (filing/commenting elsewhere, not part of this report):

• App crash itself may be related to a Cloudflare connection error that appeared before

closing, while VPN was active — cause unconfirmed.

• After reinstall, Code tab sidebar didn't show previous sessions even though the .jsonl

files still exist under ~/.claude/projects/ (see #81907, #62997).

• Scheduled Tasks were lost entirely since they're local-only, not synced (see #56372).

Screenshots attached: Start menu during failed reinstall, .claude/projects folder showing
session files intact (folder names redacted for privacy).

<img width="571" height="563" alt="Image" src="https://github.com/user-attachments/assets/5e57b520-909f-4171-8942-3e6c714bd39b" />

<img width="843" height="429" alt="Image" src="https://github.com/user-attachments/assets/dd8c03a7-3d4a-447c-9abd-a008c01c38c0" />