For PC Users:
Did you just recently update iTunes? There's a known issue posted on the Apple discussion boards that sometimes iTunes updates will block third party applications (like TuneUp) from communicating with iTunes. In other words, after updating iTunes, TuneUp no longer "sees" that you've dragged and dropped a song.
The easiest way to resolve this is to completely uninstall iTunes through the Windows Control Panel then reinstall iTunes "fresh" from the Apple website:
http://apple.com/itunes
Can you run through that and see if it resolves your issue? If not, it sounds cliche, but can you also uninstall TuneUp and reinstall fresh so we have a clean slate for troubleshooting?
http://www.tuneupmedia.com/Redirect/winDownload
If you're still experiencing issues with TuneUp after reinstalling as per the above instructions, please
contact support and mention you've followed these steps! Thanks in advance!