Windows installer silently fails on clean machines without VC++ Runtime

Context

We discovered this while deploying Claude Code to enterprise devices via Microsoft Intune and Windows Autopilot. On freshly enrolled devices, Claude Code installs before Office 365 or other apps that typically bring in the VC++ Redistributable. The installer reports success, but the binary never actually gets placed.

This will affect any organization deploying Claude Code at scale to new or freshly imaged Windows machines.

Bug Description

The Windows installer (claude.ai/install.ps1) silently reports success when claude.exe fails to run on clean Windows installations that lack the Visual C++ Redistributable runtime (vcruntime140.dll).

Steps to Reproduce

1. Open Windows Sandbox (clean Windows, no additional software)
2. Install Git for Windows (prerequisite)
3. Run the official installer:

``powershell
irm https://claude.ai/install.ps1 | iex
``

1. Observe output says installation complete
2. Run claude - command not found
3. Check ~/.local/bin/claude.exe - file does not exist

Expected Behavior

The installer should either:

• Detect the missing VC++ Runtime and install it (or prompt the user)
• Report the actual failure instead of claiming success
• Verify the binary exists after claude.exe install and report an error if it doesn't

Actual Behavior

• claude.exe install fails with exit code -1073741701 (0xC000007B / STATUS_INVALID_IMAGE_FORMAT) because vcruntime140.dll is missing
• The installer script does not check the exit code
• The installer does not verify the binary was placed at ~/.local/bin/claude.exe
• Reports success despite nothing being installed

Error Codes Observed

| Code | Hex | Name | Where |
|------|-----|------|-------|
| -1073741701 | 0xC000007B | STATUS_INVALID_IMAGE_FORMAT | Fresh Windows 11 VM (Autopilot) |
| -1073741515 | 0xC0000135 | STATUS_DLL_NOT_FOUND | Windows Sandbox |

Both point to the same root cause: claude.exe v2.x dynamically links vcruntime140.dll which is not present on clean Windows installations.

Environment

• Windows 11 Enterprise 10.0.26200 (Windows Sandbox and Hyper-V VM)
• Claude Code version: 2.1.71
• PowerShell 5.1
• Clean Windows with no VC++ Redistributable installed

Notes

• Most developer machines already have VC++ from VS Code, Visual Studio, Python, etc., so the issue only surfaces on clean Windows installations
• Our workaround for Intune deployment: bundle vcruntime140.dll + vcruntime140_1.dll (173KB total) in the deployment package and place them next to the binary using Windows DLL search order (application directory is checked before System32)

Suggested Fix

In install.ps1, after running claude.exe install:

1. Check $LASTEXITCODE for non-zero values
2. Verify the binary exists at the expected location before reporting success
3. Optionally: detect missing VC++ Runtime and either install it or provide a clear error message