I have a 2500+ at 3200+ so I know how to do it to 3200 speeds easily (as long as nothing else inside complains

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Go into bios, the FSB should be at 333 (or 1 mhz around it) right now. Change it to 400 and your set. Now also, you do have PC-3200 ram right? (just to make sure it can handle 400 fsb without any problem)