IE5 start page keep changing automatically

i've set my start page to Google, but every time i reset, or turn off/on my computer, it resets to

http://www.gohip.com/browser/?pid=AAAAAAAAAAAAHW&ence=&...

what this does, is download their little sidebar, which goes above my start menu on my desktop, then send me to google. there's no way to turn the damn thing off, so i do ctrl+alt+del, and end the task, then i go to my Internet Options and change my start page back to google. this works, until i reset my computer. after i reset, or turn off/on, it goes back to the other one. what do i need to do to keep my start page as google and not change all the time.