Quick question. My p4 2.6 seems to running pretty cool (about 29c idle) so I thought about upping the speed a little. When I o/c as little as 2.8 windows xp won't boot. It loads and gets to the disc checking screen but after that locks up. I have an ECS 648fx-a (800mzh fsb) and 2 sticks of dual channel 256 mb kingston ram. Do I have to uninstall the cpu in xp so it reinstalls or something completly different. Appericate any help thanks guys.

Have you locked AGP/PCI at 66/33? Have you set the timings right for your RAM? Have you tried to up the Vcore a notch? How about DRAM voltage? You raised the FSB moderately, from 200 to 215, but if you chose 1:1 ration, your RAM is at 430 right now.

P4 boards are pretty easy on AGP/PCI speed. In another word, overclocking 10-20% without AGP/PCI locked does not present any problem most of the case. Like Shawn said I'd bet that the memory setting is the problem specially in 800mhz P4. Try use 5:4, or 3:2 memory ratio. You may need to increase Vcore if the memory setting change does not solve the problem.

Thanks for the advice. I set the clock speed to 2.8 w/ 5:4 settings but to no avail. It seems that with the 3:2 settings I can't even get windows to start booting. Now im not sure how to set the AGP/PCI locked to 66/33, maybe its my cheap ass mobo that won't let me. I've also noticed that I can't change the voltage core and haven't had any luck finding bios updates. I did however find the dram timing control/latency and all that good stuff, but didn't know if it pertained to my problem. Any more advice? Thanks again -matt zep

Are you using a Serial-ATA Hard Disk. I've observed that FSB overclocking invariably creates problems when using SATA so if you are overclocking better go along with conventional PATA.