Fatal error! Exception: (Access Violation) Plz help!

[Ginsain]

Greetings everyone
I am on week 3 trying to find out what exactly my problem is, and why I keep getting the following error while using ANY of my large applications i.e games etc. After a certain time I will get a windows error message saying:

"this application has encounter a critical error.
FATAL ERROR!
Exception: 0xc000005 (ACESS VIOLATION) at 001B:6f07e945
001B:0d5b0339
The instruction at '0x6f07e945' referenced memory at '0x0000000c'
'0x00000687'
The memory could not be read"

Thereafter the application has been shutdown and I'm back on my desktop. When I'm not so lucky enough to get the error with this happens, the PC will just simply completely reboot out of no where right in the middle of what ever I was doing.

System specs:
WIN XP HOME
Compaq
850MHz PIII
40G
256 SD RAM
on board graphics IntelR 82810E Graphics Controller (Disabled in profile)
NVidida e-TNT 2 M64 32MB PCI Version ( Active graphics card) current drivers

I have fresh HD, Fresh installation of windows xp, completely updated with windows update.
I am lost atm, so any help or direction you could provide would be greatly appreciated.

Thank you very much!

[s7p9a2m4]

I suspect bad ram. You can try to test with memtest.
http://www.memtest86.com/
Or if you have more than one stick of ram, try removing one at a time to find the bad one.

[Ginsain]

Alright Ill try another stick and see what happens thanks.