0xC5 Blue Screen

Hello,

Recently my computer has been restarting on its own, usually when multiple tasks were running. Most of the time I had an internet browser running (Firefox, IE or Google). After some research I realized "Automatically Restart" on System Failure was checked. After disabling this option I received a blue screen with this error during the next system failure:

0x00000c5 (0x0007FF3F, 0x00000002, 0x00000001, 0x8054B168)

Windows XP Media Center
Gateway
AMD Athlon 64 x2 Processor 3800+

Note: I haven't had any anti-virus softwares since I bought this PC several years ago. Last free online scan was clean, as were several spyware scans (scanned about a week ago when the problem first started to occur).

Other than this my computer seems to be running nicely, except one peculiarity with Firefox in which it will no longer remember my login information on websites I frequently use. Internet Explorer and Google Chrome cookies seem to be working fine though.

 

Okay, I had another blue screen now which says:

IRQL_NOT_LESS_OR_EQUAL

0x000000A (0x00000010, 0x00000002, 0x00000001, 0x805172D6)

Looking this error up, it seems it might be a hardware issue... : (

Yet, with the two messages being completely different I'm not sure what could be the problem.

Edit: Oh yeah, I was running Malewarebytes, Google Chrome and an online game when it crashed...