I can't seem to get Itunes 8.2.1.6 to run

Hello,
Hi, i can't seem to get Itunes 8.2.1.6 to run. Each time after the installer is launched, it has an error message that says "The system encountered error efore Itunes could be configured. Your systems has not been modified. To try this application at a later time, please run the installer again."

I have done it a dozen times. Uninstall and reinstall. SAME ERROR MESSAGE!!!

please help.
very frustrated. thx

Configuration: Windows Vista
Internet Explorer 7.0