WPrime error in Vista

I've read that WPrime is better to run in Vista. So I tried to install it today from several different links including HWbot. Each time I try to run it a windows pop up states unexpected error; quitting. WPrime runs fine in XP though. Any ideas what might be causing this as?

Right click the WPrime executable or shortcut and select "Run as administrator".

Replied to quick, I just figured it out. Thanks anyway.

What was the problem?