"zotero is already running. please close zotero before running the installer."

Morshedzim · 2026-05-04T13:44:06+00:00

I uninstalled zotero and tried to reinstall it for some reason. i uninstalled it using revo uninstaller, and then tried to install it again and it said "zotero is already running. please close zotero before running the installer." I manually checked for all the possible location and manually deleted them all. also checked %appdata% and %localappdata%, there is nothing. restarted my PC. tried again and again popped up "zotero is already running. please close zotero before running the installer"

https://s3.amazonaws.com/zotero.org/images/forums/u20433578/vdgl8t4gtn7zvytixc0n.png

dstillman · 2026-05-04T17:09:48+00:00

If you have C:\Program Files\Zotero or C:\Program Files (x86)\Zotero, delete them.

Look for zotero.exe in Task Manager.

Morshedzim · 2026-05-04T18:48:52+00:00

Checked task manager,there is nothing.

dstillman · 2026-05-04T18:54:13+00:00

You should also delete those folders if they exist and restart your computer.

You should also run Task Manager with elevated privileges and check for processes running in another OS account, etc.

Non-standard security software on your system could also be interfering.

This is simply a check for zotero.exe, so something is causing the installer to think that process is running.