A computer on the brink of death, HELP!

Friends computer is messing up.. this is this information ive aquired from him.

"Last night, out of nowhere my computers screen screwed up and became blue and white(mostly blue). After a while of hoping it may come back, I restarted the computer, and the boot up graphics were completely messed up, and eventually it just died. I tried again, this time unplugging, same.(the mess-up was different on the graphics)

This morning, I tried starting it up, and the IBM boot-up screen came up. It told me that something was wrong with a media cable, and no operating system was detected. After 3 tries(off/on) the computer booted up normally, but I left it alone for 20 minutes and I came back to find it off(still running, but appeared to be shutdown). I restarted it again, and it worked, and on the desktop windows reported that the graphics card had caused the shutdown. Right now it appears to be functioning normally.

I use a Nvidia Geforce 6700 LE (PNY), Windows XP, and a 2.4gh CPU. Please help, I can't afford to replace my computer."

Above all that, there is random changes in his registry, internet and PC has become extremely slow, when left alone, there was unexpected shutdowns, and when he touched a wire behind his floppy drive, his monitor went black and the IBM boot up screen appeared.

The registry changes were caught by spybot.

I myself am not sure whether this is a hardware or software issue (because of the registry changes), but if this is in the wrong section sorry before hand.

 

Anyone?

 

Take one sympton at a time.
The apparent shutdown, when left alone appears to be hibernating - Try right click desktop, click properties, click power, on the hibernate tab, make sure hibernation is unticked, you can also , on power schemes , change all to never,
You can change times to suit you if you want to have the screensaver come on, when left alone.

 

For the graphics cardd, it is worth checking if you have the latest update for it, as it could just be a faulty driver.
http://www.nvidia.com/object/winxp_2k_162.18.html

 

If you still have problems:-
Always switch off, and disconnect the power cord before checking inside the computer.
Look inside, and take antistatic precautions (wrist strap is best), like touching a good earth point like a pipe, or radiator, if nothing else, and touch the chassis with both hands, before touching anything inside the computer- in fact if you have no earth strap, and nothing to earth yourself, leave the plug attatched , but switched off at the mains, and touch the chassis , then remove the plug, as this will earth you via the plug earth, and then check all the Ribbons, and power connectors to the floppy etc: leads connecting are good, by easing them off , then back on , again.
Plug mains back in, and restart.
If no problem restarting then shut down, again, and check the graphics card , by unscrewing the backplate, removing, and replacing the graphics card.
Ideally ,if you get yourself an airasol spray (buy at any computer store) clean out dust and fluff with this, WHEN COMPUTER IS COLD BY BLOWING OUT WITH THE AEROSOL.

 

If you run these checks, and you still get random shutdowns, as you mentioned spybot finding problems in the registry, then consider a further malware check- Microsofts own is free to run a check, and it also checks your registry.
http://support.microsoft.com/kb/890830