hi mark
had this problem a while ago, did not need anything fancy to fix it. go to "computer active " web site and on there you will find a little program called "start page guard" it does exactly what it says, stops anything from hi jacking and redirecting your opening browser page. its free, it is not spyware, and it is clean because it comes from a reputable source.
hope this helps, i've been using it for months now and had no problems with it
cheers