Same problem here: Windows Uninstaller is not working. I use Version 220.127.116.119 Then I tried the clean tool mbam-clean-18.104.22.1681 but I just read here that that is designed for version 2, not 3. (I really hope running it didn't screw up anything else.) So I went with Porthos suggestion: Reinstall it. I tried that, but get an error during install: C:\WINDOWS\system32\drivers\mbase64.sys An error occured while trying to replace the existing file. DeleteFile failed: code 5. Access is denied. Click retry, etc, etc.. So I click Cancel (as advised), and it rolls back changes. I am getting a bit desperate. I wanted to try malwarebytes, so I installed the lastest 22.214.171.1249 It didn't work (I only get 'Unable to connect to service'), so I decided to unintall. Tried windows uninstall: Error Tried clean-up tool: Works only for version 2. Tried re-install over the former install: Error (above). Please help: How do I get it out of my PC?