Windows Process "Preview Handler Surrogate Host" Causing Issues

[MitchellT2]

As described in the title I am having issues with VM's deployed via RAS where if a user is using the preview feature in File explorer they are unable to delete files as a pop up saying the following stops the deletion "This action can't be completed because the files is open in Preview Handler Surrogate Host"

I would like this to be fixed on a template level and no turning off preview in file explorer does not fix it
Using Microsoft Power Toys and specifically File Locksmith the Proccess "prevhost.exe" is the one stopping you from deleting the file
Ending the proccess is not suitable as users need to see the preview of files

Any assitance would be appreciated

 

[TonyS25]

This sounds like a Windows File Explorer/Preview Handler issue rather than a RAS-specific problem. prevhost.exe is the Preview Handler Surrogate Host, and similar cases have been reported where previewing files leaves the file locked and prevents deletion.

Since users need the Preview Pane, I would avoid killing prevhost.exe or disabling previews entirely. On the VM template, I’d first make sure Windows is fully patched and check which file types reproduce the issue, as different preview handlers can behave differently.

I’d also test the same template without RAS. If the problem occurs there too, that would help isolate it to Windows/Explorer or a third-party preview handler rather than the RAS deployment.

If it happens only with RAS sessions, I’d collect the Windows build, RAS version, affected file types, and preview-handler details and raise it with the RAS vendor. There are documented cases of preview handlers causing file-locking problems on Windows, so your prevhost.exe finding is a useful clue.