pc keeps rebooting (blue screen)

Hi,

After reading previous threads I decided to implement the advice before posting my own thread but I have had no such luck so far so I am posting my own thread of the problem.

pc-
intel p4 2.8ghz ht fsb 800mhz, gigabyte 8knxp ultra rev 1.0 motherboard, 512mb ddr ram (2 sticks of 256 -dual channel), sata hd, ide hd, ati 9700 aiw 128mb graphics card, onboard sound & lan, 500watt power supply, XP pro service pack 1.

problem-
blue screen of death

The computer has rebooted from a bugcheck. The bugcheck was: 0x1000008e (0xc0000005, 0x80608c6b, 0xb9dca930, 0x00000000). A dump was saved in: C:\WINDOWS\Minidump\Mini022606-01.dmp.

The computer has rebooted from a bugcheck. The bugcheck was: 0x1000008e (0xc0000005, 0x00000000, 0xaff3e6d4, 0x00000000). A dump was saved in: C:\WINDOWS\Minidump\Mini022406-01.dmp.

among others...

often the blue screen refers to graphics adapter, requesting me to disable caching shadowing, my bios does not have these options (even though i'm running latest bios).

I recently purchased new ram (2 sticks 256mb kingston) and replaced current, however i used different dimm slots (still at dual channel).

Already tried memtest on old ram it passed 7 times.

did a dumpchk on minidumps it refers to sound drivers (maybe i am wrong), not sure what to do next.

attached minidumps with this message, can please please someone help.

thank you in advance.