i can't get itunes off my c drive!

I am running windows vista home ed on a lenovo. I followed the instructions to move itunes music from c drive to d drive, so I could free up hard drive space on C. It was using around 23 GB. I can see now when I access music in itunes that it is coming from D drive. However no space was freed up on C even though I moved to recycle and emptied and restarted. Something is still taking up around 20GB on C but I can't find the itunes music folder there anywhere. I had to dump office just to make enough room to do updates! HELP!