I have CCleaner set to run silently before shutdown and never had a problem, but the other day I updated to version 3.13 and all of a sudden I started getting the message "Windows Explorer has stopped working" at startup. Restarting explorer.exe didn't help, it kept failing so only restoring an image could get me out of this loop. After testing and retesting (to exclude other possible causes) I had to conclude there was one culprit and that was CCleaner. I have gone back to CCleaner 3.12 and all is well now again. Posting this here for your information. Best regards, Sarah. Edit: I work with Vista Home Premium.