blue screen error in xp help please

I have a PIII with 256ram, on which i run XP pro.  After two years of crash free usage, i started getting the following blue screen error immediately after i boot.

driver_irql_not_less_or_equal
0x000000d1(88d0b966,0x00000002, 0x00000000, 0x88d0b966)
tcpip.sys address f4de4843 base at f4de2000 date stamp 3b7dc580

i tried to shift(got vexed with this screen so much) to win2k but it too started giving similar (not same) error message. So i got into win98. No such messages.  But my other partition still has xp and i want to use it(i am addicted to xp).

By the way, i use a cable conncetion for internet.

Please help  (I am no geek) and fast pleeeeeeeeeeeeeeeeese.Thanks for ur time.
vij