What browser are you using?? Internet Explorer users are more vulnerable for browser hijacking and spyware attacks because its a very insecure browser. I recommend switching to FireFox (you can read the thread about it here: http://petoftheday.com/talk/showthread.php?p=1325523 ).

As for spyware and malware, etc, I strongly recommend downloading, installing, and running these programs multiple times a week (if you don't already!)

- Microsoft AntiSpyware
- Spybot Search & Destroy
- AdAware
- AVG AntiVirus
- OPTIONAL PeerGuardian

I have all programs and run them AT LEAST weekly if not every other day and also use FireFox and my computer has not had ANY problems concerning viruses or browser hijackings in... almost two years now

EDIT: OH I forgot to add, a good program to use if your browser gets hijacked (or for IE) is a Browser Hijacker removal. I can't think of a specific program to use since I haven't needed one in years after switching from IE to FireFox.