redirect virus help needed!

Calling out to anyone who can advise or help!

I appear to have got somekind of redirect virus on my laptop (an HP one, running Windows XP).  When I try to search for something using a search engine it redirects me to random search websites. I've managed to do some limited searching, enough to gather that I'm not the only one to have this problem, but not enough to find out how to cure it!

Any ideas anyone??

Oh, I'm also running Norton Antivirus software (which I gather is not everyones virus software of choice!).