I would not bother trying to overclock that Celeron chip by even 1MHz. It's pointless to overclock those chips. If I were you, I'd maybe keep the hard drive and any other CD/DVD drives you have... Pick up a new case, motherboard, CPU, faster RAM, and PSU. Even a cheap C2D Conroe would kill your Celeron right out of the box. A decent board can be bought for $100 or even less. Only do this if you're actually going to be using the processing power that you gain from upgrading. I upgraded last month from a Pentium D 2.8GHz to the new Wolfdale E8400 with a $90 Gigabyte P35-DS3L motherboard, and with the same memory and graphics card, this thing blows my Pentium D system out of town. It's like comparing a PSOne to a 360. That's the performance I gained.