Hey there cookiecrumbs123,
It sounds like you are unable to open iTunes unless you are in Safe Mode on your PC. I would use the step in the following article to help resolve these issues you are seeing in iTunes. It starts off with troubleshooting for 3rd party plugins to boot!
iTunes for Windows Vista, Windows 7, or Windows 8: Fix unexpected quits or launch issues
http://support.apple.com/kb/ts1717
Start iTunes in Safe Mode
Open iTunes in Safe Mode to isolate any interference from plug-ins or scripts not manufactured by Apple.
Hold down Shift–Control while opening iTunes. You should see a dialog that says "iTunes is running in safe mode" before iTunes finishes starting up.
Click Continue.
See if the issue you're experiencing persists in Safe Mode.
If you have the same issue while iTunes is in Safe Mode, proceed to the "Create a new user account" section. If you don't experience the same issue, follow these steps to remove third-party plug-ins.
The article has additional steps to help isolate the issue to being either system wide, or user specific with troubleshooting for each so if it is not a plug in causing it, there is more for you to try.
Thank you for using Apple Support Communities.
All the best,
Sterling