What the Reverend said.

There are many BSOD, but only one where IRQ_L is not less or equal ... it pertains to memory addressing. Like Rev said, remove one stick and run the PC. If the error occurs again > swap the sticks < and make sure you only run the PC with one stick. The chances of both sticks being bad are very low ... unless both sticks were mishandled before installation. Be sure to seat the sticks properly. Even one stick mis-seated will cause the BSOD you are receiving. Like Rev said, XP utilizes RAM differently than Win2K.