Blue screen error

Hi,
Each day, I am getting same error... for few times per hour. Pc suddenly shut down, and I can see blue screen. It says:
DRIVER_IRQL_NOT_LESS_OR_EQUAL
bla bla bla,

NDIS.sys - Address f82acbef base at f8296000, DateStamp 41107ec3
Beginning dump of physical memory
Physical memory dump complete.
Computer dont have any virus, or worm.. Event Viewer shows this every time after crash:

Error code 100000d1, parameter1 00000008, parameter2 00000002, parameter3 00000000, parameter4 f82acbef.

For more information, see Help and Support Center at:
microsoft web page (link is not allowed here ;])

I have read many instructions on the net, in your page, I even found guy, whose had same trouble. I have checked my rams for 30 times- No one error. I have checked my Hard Disk sectories- no error, I have changed CPU thermal past, but there is no broblem too- every part of hardware have perfect temperature...

Operating System : Microsoft Windows XP Professional 5.01.2600 Service Pack 2
Processor : Intel Pentium 4 @ 3000 MHz
Video Card : NVIDIA GeForce 6600
Ram: 512MB DDR-SDRAM
Hard Disk : WDC (160 GB)

Only one thing, whereof I dont know, is PC Power supply box... When I switch my pc, it starts burr (fan inside), but after some time, it starts work good. Should I change it, if I dont know who is wrong? I am not a millionaire, so when i persuade whose wrong, then i'lllook for the new one.. Waitting for informative answers :)

0xD1 errors are caused by either faulty drivers of faulty software. NDIS.sys is a core Windows driver which is too general. From what I have briefly researched this can be due to faulty NIC drivers. Update your NIC drivers.

Hi, I am getting the following blue screen. This happens when I play far cry 2. Can you please indentify the culprit?

I have ran Prime95 and memtest and everything seems to be ok. I have also attached the minidumps.

Thanks

0xD1 errors are caused by either faulty drivers of faulty software. NDIS.sys is a core Windows driver which is too general. From what I have briefly researched this can be due to faulty NIC drivers. Update your NIC drivers.

Okey, I have downloaded some versions of "Realtek RTL8139/810x Family Fast Ethernet NIC" drivers, but just as I trying to update (instal), inst.wizard gets lagged on the end of "Instaling drivers"..
At control panel, when I am trying to update network adapter (same one), wizard is searching for drivers, but I need to press "cancel couse It doesn't find anything for longish time period... Could you say some instruction, what should I do this way?

MotherBoard: ASRock P4i65PE
Connect using: Realtek RTL8139/810x Family Fast Ethernet NIC