ok everyone ive posted a few things about my cpu only running games if i underclock it well i ran prime95 on the cpu when it was set at its proper speed 2600+ 166x12.5 2.08 ghz, heres the results first time, prime 95 crashed after 4 minutes second time, started prime95 and pc reset itself after 4 minutes third time, prime 95 came back with a cpu error after 9 minutes im currently running my cpu at 165x12.5 2.06 ghz and prime 95 has been running for about 25mins no errors so far! does this mean that its most probably my cpu thats at fault? as i said b4 ive ran memtest and it found no errors, could it be the motherboard or something else??? ive also tried 163x12.5 and it ran without any problems. also the voltage of my v core is 1.66 sometimes drops to 1.65 is this normal did this with my old 350 watt psu and now my 550 watt also my 12+ is at 11.67 and drops to 11.55 sometimes is this normal? does this no matter what my cpu is clocked at. thanks in advance

OK Rocky, I got sick of your posting about the same thing so I decided to download your motherboard manual & have a look...I have a suspicion I know what's happening. You have two FSB jumpers on the motherboard, right next to the RAM slots. Did you ever set it to 166? If not, that's your problem...it's probably set at 133, which would explain why you're stable from 133-165mhz, but not at 166mhz. All you have to do is put the jumper caps on pins 1-2 on both FSB_SEL0, & FSB_SEL1...that will enable FSB settings from 166-199mhz.

it was setup when i bought it, and it is setup properly ive just taken a look but thanks for the info anyway.

rocky, you said this is a new computer. take it back to the store & tell them to fix it.

There have been several versions of the XP2600+: Aug 2002: Tbred B 266FSB 2.133GHz (16.0x133) Nov 2002: Tbred B 333FSB 2.083GHz (12.5x166) May 2003: Thorton 333FSB 2.083GHz (12.5x166) Jun 2003: Barton 333FSB 1.917GHz (11.5x166) Are you sure you do not have last version?