Processor Unknown / settings

I need some help... i'm average user (know enough to get into trouble, but not enough to fix by self). My bios and my winXP will not reconize my CPU Model, i have a nvidia A939 mobo with altholon 64x2 processor, i know its a duel core hammer family but dont exactly know which one and system is not seeing it either. With everything i put into this system for gaming it should NOT lag yet it is, i understand that game server lags (granted) i even understand my ISP really SUX but both together dont account for lag i get.

XP home (upgrade), AMD Hammer Family Processor, 2.21 GHz, 3.00 GB ramm (kingston dual layer), NEC flat screen monitor, radeon x700 pro PCIE video, 80GB primary HDD (seagate), 200GB SATA maxtor logical secondary HDD, DVD +-R x2.

Occasionaly when i play games OFFLINE i still get some lag, and when i look at cpu usage its CONSTANTLY at 100% with ram at 25(ish)%.... can someone help me figure what settings i screwed?