What cause and How to fix the "another program is using this file" error

The missing search bar and the error when opening the Search app indicate a Windows Search component problem, not a simple “file in use” situation. The error text is generic; the underlying cause is typically corruption in the Search app’s data or registry, or a policy blocking the Search app.

Use these steps, in order, on Windows 11:

1. Test with a new user account
   • Create a new local user account and sign in with it.
   • Check whether the search bar and Search app work there.
   • If Search works in the new account, the issue is specific to the original profile and the next steps focus on repairing that profile’s Search data.
2. Regenerate the Search app data and registry for the affected account
   • Sign out of the affected account and sign in to another admin account, or use Windows Recovery Environment as noted below.
   • For the affected account, delete the Search package data folder:
     • On Windows 11, delete: %USERPROFILE%\AppData\Local\Packages\MicrosoftWindows.Client.CBS_cw5n1h2txyewy (In some earlier builds this folder might be named Microsoft.Windows.Cortana_cw5n1h2txyewy.)
   • Sign in as the affected user.
   • Open Registry Editor (regedit.exe) and go to: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Search
   • Delete the Search key.
   • Open an elevated PowerShell window and re‑register the Search app:

          Add-AppxPackage -Path "C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\Appxmanifest.xml" -DisableDevelopmentMode -Register
     

   • Restart the computer.
   • After restart, try the search bar and Search app again. This forces Windows to recreate the Search registry key and AppData folder and restart indexing.
3. Check for AppLocker or policy blocking the Search app (if on a managed device)
   • If this PC is managed by an organization (work/school), the Search app can be blocked by AppLocker or Group Policy.
   • In that case, an admin should:
     • Review AppLocker logs for entries like MICROSOFT.WINDOWS.SEARCH was prevented from running or errors stating the program is blocked by group policy.
     • If AppLocker is enforcing rules that block Search, remove the AppLocker rules from the applicable Group Policy Object (GPO), allow the empty policy to apply to clients, and only then disable the AppLocker service. Rules must be cleared and applied before the service is disabled, or enforcement can continue even with the service stopped.

If the problem persists after regenerating the Search package and confirming no policy is blocking it, collect details (screenshots, exact error text, and steps tried) and submit feedback via Feedback Hub under Desktop Environment → Search so the issue can be investigated further.

References:

• Fix problems in Windows Search
• Modern, Inbox, and Microsoft Store Apps troubleshooting guidance