you need to write down all of the changes you make.
then try to boot the computer at the overclocked speed, if it doesnt boot, you know you need to up the voltage.
Because you wrote it down, you can reset the CMOS and put in the overclocked numbers back in and up the voltage just a little bit. maybe .2volts.
try to boot again and if it doesnt boot, you need to reset the cmos and up the voltage a little bit more.
You just always need to remember to write down all changes you make to the bios. Its a lot of nubers to remember off the top of your head.
i suggest you read the overclocking sticky for this forum.
AMD Athlon 64 3200+ \"Venice\"
2GB OCZ Platinum DDR400
eVGA 256mb 6800GT
ANTEC 430watt TruePower 2.0
WD 160GB 8MB cache HDD
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