Download a program called "Hijack This". I fix many of my friends computers, and they'll pick up this problem sometimes at questionable websites. More than likely, besides hijacking your current home page setting, the javascript or active x component also changed registry settings which will change it back again after you fix it when you reboot. You'll likely need to change those registry settings to prevent a re-occurance. The easiest way for a novice is third-party utilities such as Hijack This. I believe the utility is still available as freeware at cnet.com, for example.
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