One of the users on my computer cannot open an explorer window. Any attempt to do so, whether by running explorer.exe directly, by opening a folder shortcut, or attempting to open the Control Panel gives an error:
Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.
They are able to browse the file system normally from File/Open application menus, but "Open in new window" fails with the same error. The only solution is to turn off UAC, and add this user to the administrators group. Other standard users can open explorer normally with UAC on.
If they close the shell explorer.exe process from Task Manager, they can restart it. However, subsequent attempts at running explorer fail. Attempting to start explorer as a new process fails with the same result.
If I make a copy of explorer on the user's desktop, trying to run the copy gives the same error. If I rename it, nothing happens when it's run.
The security settings for explorer.exe are in order. I've run chkdsk and sfc, but they find no errors. I turned on all auditing for explorer.exe, and system-wide auditing for access failures, but the event log yields no clues.
There's a similar question at Only Administrator can use Windows Explorer. Normal users get an error when accessing Windows Explorer, where the poster gave up and just created new accounts. I'd prefer to fix the problem, if possible, rather than risk running into more issues by copying all their settings to a new account.