I have tried to overclock my Intel 2.67GHz processor through motherboard BIOS setup.

After boot up. Some applications such as onboard sound device was not working and internet speed also downed.

But after this when I set up the BIOS settings into default(previous state) . Computer seems to work well..Sound + Internet also fine work (in default processor speed)

If any one know how to overclock cpu without having trouble please tells me.
I am using Windows XP SP2

Hello and welcome to Techspot Xmm ! What processor do you have by the way (Pentium 4, Celeron D, Pentium D, Pentium M Laptop, Intel Core 2 Duo, etc.)? The only problem with overclocking is that it can damage your computer as well as overheat it. Instability can also be caused by overclocking too. IF you are not that experienced with computer hardware I would not suggest that you overclock your CPU.

Overclocking usually means increasing the speed of the PCI Bus and that means everything on the whole system is affected. Pretty much anything could become unstable unless you have a PCI/AGP lock or a PCI/PCI-E lock.

what brand, model, and chipset is your motherboard?