Search pages Hi-jacked Please help.

Ok heres the problem, all of the search pages i go on google, yahoo ect are being hijacked by some kind of ActiveX script ive tried removing this problem on my own, i got it from tampering with my results to show only ones from certan sites where they want you to buy stuf, to just blocking the ActiveX script and not letting me on to the page at all. So any information you guys could give me i would be very gratefull.
Thanks in advance Chris.

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