WSL2 fails to mount C:\Program Files\WSL\system.vhd with HCS/ERROR_NOT_FOUND when converting distro to version 2

[SwordOnline1]

Windows Version

Windows 11 23H2 OS Build 22631.4169

WSL Version

2.6.3.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

6.6.87.2-1

Distro Version

Ubuntu 24.04.4

Other Software

No response

Repro Steps

1. wsl --set-default-version 1
2. wsl --install -d Ubuntu
3. Ubuntu installs successfully as WSL1
4. Run wsl --set-version Ubuntu 2

Expected Behavior

Ubuntu should convert from WSL1 to WSL2 successfully.

Actual Behavior

Conversion fails with:

无法将磁盘“C:\Program Files\WSL\system.vhd”附加到 WSL2: 找不到元素。
错误代码: Wsl/Service/CreateVm/MountDisk/HCS/ERROR_NOT_FOUND

Additional Notes

• wsl --version works normally
• wsl --install -d Ubuntu fails under WSL2 path, but succeeds under WSL1
• Microsoft-Windows-Subsystem-Linux is Enabled
• VirtualMachinePlatform is Enabled
• DISM /Online /Cleanup-Image /RestoreHealth completed successfully
• sfc /scannow found no integrity violations
• C:\Program Files\WSL\system.vhd exists
• net start vds was tried, but the issue remained

Diagnostic Logs

I collected logs with collect-wsl-logs.ps1.

WslLogs-2026-03-20_21-00-35.zip

[github-actions]

Diagnostic information

Detected appx version: 2.6.3.0
Detected user visible error: Wsl/Service/CreateVm/MountDisk/HCS/ERROR_NOT_FOUND

[chemwolf6922]

Hi @SwordOnline1, The problem could be that the wslg system.vhd is broken. Could you please try disable wslg by editing the .wslconfig file and try again?

[wsl2]
guiApplications=false

If that does not work, please try reinstall wsl and see if that works.

[SwordOnline1]

I tried disabling WSLg by creating %UserProfile%.wslconfig with:

[wsl2]
guiApplications=false

Then I ran:

wsl --shutdown
wsl --set-version Ubuntu 2

The same error still occurs:

Unable to attach disk "C:\Program Files\WSL\system.vhd" to WSL2: The element was not found.
Error code: Wsl/Service/CreateVm/MountDisk/HCS/ERROR_NOT_FOUND

[SwordOnline1]

I checked the Windows Installer logs after re-running wsl.2.6.3.0.x64.msi.

The repair/reconfiguration did not succeed. Event Viewer shows:

• Product: Windows Subsystem for Linux -- Configuration failed.
• MsiInstaller event ID 11729

The same error still occurs when running:
wsl --set-version Ubuntu 2

Error:
Unable to attach disk "C:\Program Files\WSL\system.vhd" to WSL2: The element was not found.
Wsl/Service/CreateVm/MountDisk/HCS/ERROR_NOT_FOUND

[SwordOnline1]

I performed a clean reinstall of WSL and reinstalled Ubuntu.

Current results:

• wsl --version works normally
• wsl --install -d Ubuntu succeeds
• Ubuntu installs and runs successfully as WSL1
• wsl --set-default-version 2 succeeds
• But converting Ubuntu to WSL2 still fails with the same error

Command:
wsl --set-version Ubuntu 2

Error:
Unable to attach disk "C:\Program Files\WSL\system.vhd" to WSL2: The element was not found.
Error code: Wsl/Service/CreateVm/MountDisk/HCS/ERROR_NOT_FOUND

So after a clean reinstall, WSL1 works, but WSL2 still fails at mounting C:\Program Files\WSL\system.vhd.