I'm nearly 100% sure that processor is Slot one, and I know that Celeron isn't... If you want to upgrade, you'll have to get another slot one. They have around 1GHz Pentium III slot1's. There's also a converter from Slot1 to Socket370, but those tend to have compatability problems.
__________________
Desktop * Athlon X2 4200 | 2G RAM | 160G HD | 7600GT
Laptop1 * C2D T5550 | 3G RAM | 120G HD | Intel x3100
Laptop2 * C2D T5250 | 2G RAM | 160G HD | Intel x3100
|