How to Fix "PDF File Locked by Another User or Process" Error in Windows

Windows blocks the change because some program still has the PDF open, even if you cannot see it. The usual culprits are the File Explorer preview pane, a PDF reader that is still running in the background, a browser tab showing the file, cloud sync, or, on a shared drive, a colleague who has it open. Close the file everywhere and press Alt + P in File Explorer to turn the preview pane off. If that does not free it, use Resource Monitor or PowerToys File Locksmith to see exactly which process holds the file, and end that process.

Why Windows refuses to rename or delete an open PDF

When a program opens a file on Windows, it says what others may do with it at the same time: read it, write to it, or delete it. Most PDF readers allow others to read the file but not to delete or overwrite it while it is open. That is why you can often still copy a locked PDF but cannot rename, move or replace it. The block lasts until the program closes the file, which a crashed or hidden process may never do.

The message varies. You may see The action can't be completed because the file is open in Adobe Acrobat, which names the program, or just open in another program when Windows cannot tell. In Acrobat, trying to save over the same file can fail with a message that the file may be read-only or that another user may have it open.

Fixes, from quickest to most thorough

1. Close it everywhere and turn off the preview pane

1. 1.Close the PDF in every reader, and close any browser tab that is showing it. Check the system tray for a PDF app that minimizes there instead of closing.
2. 2.In File Explorer, press Alt + P or choose View > Show > Preview pane to turn the preview pane off. The preview pane loads the PDF through a preview handler that can keep it open after you click away.
3. 3.Click into a different folder, then come back and try again.

2. Find the process with Resource Monitor (built into Windows)

1. 1.Press Windows + R, type resmon and press Enter.
2. 2.Open the CPU tab and expand Associated Handles.
3. 3.Type part of the file name in the search box next to it. Every process with that file open appears in the list.
4. 4.Right-click the process and choose End Process. Save your work in that program first if you can, because ending it discards unsaved changes.

3. Use PowerToys File Locksmith from the right-click menu

Microsoft's free PowerToys includes File Locksmith, which is quicker if you hit this often. Turn on Enable File Locksmith in PowerToys, right-click the PDF, choose Show more options, then Unlock with File Locksmith. It lists the processes using the file, each with an End task button. Processes running as another user, such as services, only appear after you click Restart as administrator.

4. Search from the command line with Sysinternals Handle

If you prefer a terminal, Sysinternals Handle lists every process with a matching file open. Run it from an administrator prompt with part of the file name:

handle64.exe contract-final.pdf

It can also force a single handle closed with -c, but Microsoft warns that this can make the program or system unstable. Ending the process is the safer choice.

5. Restart Explorer, or sign out

If the holder turns out to be explorer.exe or a preview host process, open Task Manager with Ctrl + Shift + Esc, select Windows Explorer and click Restart. The taskbar disappears for a second and comes back. Signing out or restarting the PC closes everything as a last resort.

When the PDF is on a shared drive

On a network share, the lock usually belongs to another person's session, and nothing on your PC will show it. Ask whoever has it open to close it. If they are away, an administrator of the file server can close it remotely:

• ●Computer Management: on the server, open System Tools > Shared Folders > Open Files, right-click the PDF and choose Close Open File.
• ●PowerShell on the server: Get-SmbOpenFile | Where-Object Path -like '*contract-final.pdf' | Close-SmbOpenFile

Closing someone's file this way throws away any changes they have not saved, so warn them first.

Cloud folders and brief locks

OneDrive, Dropbox and Google Drive open files to upload them, and antivirus software opens new files to scan them. These locks normally last seconds. If a PDF in a synced folder stays locked while it uploads, pause syncing from the cloud icon in the system tray, make your change, then resume. A file that is still downloading from the cloud can also refuse to move until the download finishes.

Keep working while the file is locked

Because most programs still allow reading, you can usually copy the PDF and work on the copy. The same goes for tools that only read the file and save a new one. Our browser tools work that way: they open the PDF for reading and you save the result as a new file, so the original is never written to.