BSOD 8E.etc MACHINE_CHECK_EXCEPTION and freezing problem

Hi there guys i've been experiencing problem regarding my computer lately, i always got BSOD and sometimes my pc keeps freezing in a matter of minute. ive already checked and swapped my ram sticks and i think its fine. also the hard disk is in good condition. this is my PC Specs:

Pentium D 805
Windows XP SP 3
GeForce 9500 GT 1gb PCI express x16
1GB Ram
Motherboard P5kplam-SE ASUS

sometimes i can used a coupe of 2 or 3 hrs just by using facebook and no other applications running.and when i play games its crashing. i dont know if it is in the VIdeo card since i unplugged it and plugged to the onboard video driver and i got the same error it freezes. i included the minidump files. hope you guys check it out.

Did you build this system or did you buy it from the likes of Dell, HP, etc.?

my parents bought this computer 6 years ago. and my new motherboard is 2 yrs old and my video card is 1 yr old. i dont know what's the manufacturer of this PC but it has an Sticker of PULSTAR.