Issue

Cannot delete certain folders from a network share from Windows 10 Pro desktop. The folders cannot be deleted because they contain hidden Thumbs.db files which are locked by Windows Explorer (these files are used to speed up the display of image thumbnails in  Windows Explorer icon view). Following error message pops up when trying to delete affected folders.

File In Use
The action can’t be completed because the file is open in Windows Explorer
Close the file and try again.
Thumbs.db
Type: Data Base File

Resolution

The issue can be temporarily resolved by restarting explorer.exe process, or just waiting until the lock on Thumbs.db file is eventually released. A more permanent solution is preventing Windows Explorer from creating and using Thumbs.db files on network shares. This can be done in the following way:

• Open Local Group Policy Editor (gpedit.msc)
• Navigate to User Configuration > Administrative Templates > Windows Components > File Explorer
• Enable Policy called: “Turn off the caching of thumbnails in hidden thumbs.db files“
• Restart explorer.exe process.

November 2020
Windows 10 Pro
Synology DiskStation NAS