Are you running Eset's Nod32 antivirus on that PC? If so (even if you're using
XP rather than Vista), try the measures from the following Eset troubleshooting document:
I am also having this problem where iTunes, after upgrading to the most recent version, will not close. It behaves otherwise quite normally, but when I attempt to exit the program, it will close and then immediately restart. Even when attempting to shut down the computer, iTunes will cancel the shutdown process. I have tried Force Quit, to no avail (quits and comes right back) as well as repairing my permissions, etc.
I am not running Ests or using the other products I have read could be causing this problem.
I have itunes last version and Nod32 3.xx, apply setting suggest from ESET i don't solve the problem.....i also repair installition of itune but nothis.