98, xp, vista???
You can manually go to the itunes folder in my documents & copy the tunes to a backup device, thats if windows explorer is working ok, do a ctrl alt delete & go to processes tab in task manager, click on the column for cpu which puts the listed items in order of usage & see if anything is hogging a large cpu percentage & also do the same for memory column, cause trying to do any of these will take forever if a program is hogging processing power, some updates from MS or program install/update can cause these issues where it hogs cpu at 99% & wont go anywhere quick if at all, have you done any updates, installs changes recently.
AVG antivirus is free aswell which is good to have running as has multiple tools, I've tried them all & this seems to be the best to use for free anyway at the moment for home use.
I personally would goto my documents, highlight everything, click edit at top & select copy, then goto the backup device folder/drive & click edit at top & select paste so it backs up your documents folder which from what I can see if your main usage location for files as most are.
Then do some things to resolve it if it allows you to do this of course, cause then with luck your important files are protected on the backup device.