Bad Pool Caller

Hi,

I have a Dell Precision 390 with Windows XP Sp2 on it. Recently I am getting Blue Screen on it whenever I try to boot it. On the blue screen, it gives me the error – Bad_Pool_Caller and at the bottom it shows ****npchmqsx.sys – Address F78F020E base at F78EF000, Datestamp 48b4014a.

With some googling, I am guessing that “Bad Pool Caller” could be because of some hardware issue or driver issue. But, I have no information about “npchmqsx.sys” or what this driver is about.

Any ideas?