I'm having MANY problems with iTunes lately & other suggestions haven't helped. At some time I tried to install upgrade to iTunes (to level 7-something?). Since that time when trying to open iTunes, it is RIDICULOUSLY SLOW, but given a looooooong time, will eventually open. Tried to uninstall, reinstall and cleanup. Tried to install and run Windows Install Cleanup. EVERYTHING I DO TO TRY & CLEAN UP THIS MESS results in: "ERROR 1500. Another installation is in progress. You must complete that installation before continuing this one."
Nothing shows up in Windows Task Mgr window. Nothing works. CAN SOMEONE PLEASE HELP ME?????
download fresh definitions and run vigorus spyware and virus scans. if your security software providers offer them, try online virus scans too. (they can sometimes pick up an infect even if the security sogftware on the PC has been compromised.)