ITunes error message?? PLEASE HELP!!!?

I try to open itunes but an error message saying "you dont have enough access privilages for this operation"- I dont know why it did that. I just downloaded it off itunes.com. I'm the administrator on my pc. I have Windows 7 64bit. I tried uninstalling it and reinstalling it, restarting pc,shuting off pc and letting it rest for a couple hours, and even a virus scan. I dont know why its doing this. PLEASE HELP! :(