Whats Causing The Problem??

[Dr_Seuss]

i recently turned on my computer to find a fragmented (in bands not pixels) display. the only thing im aware that has happened on the computer is a 9 hour gaming stint by my nephew; now my computer crashes every time it starts up.

ive tried reinstalling windows onto a spare disc and it began to work fine again until i connected the old hard disc using an external USB caddy and now its doing it again (no matter which hard disc i use)

at first i thought it was the graphics card but after replacing it with a friends the problem continued

.....can anyone help me find the problem (its driving me nuts!!)

computer spec:
Intel P4 Prescott 3.00GHz
2Gb 400MHz RAM
ASUS P4P800E deluxe Mobo
Gainward Nvidia FX5700 Ultra 256Mb
40Gb Seagate HDD
80GB Samsung HDD
120GB Maxtor HDD

 

[iss]

Check our ram and your PSU. use memtest and Speedfan.

 

[Tedster]

If you're getting BSODs, then zip up the last 2-3 for analysis. Also run memtest 86+ to diagnose RAM.