Hi
It looks as though you have done already what most technicians would do if it came in the workshop….
However before you consign it to the skip..for recycling of course! it would be wise to:
1 remove all peripherals ( as you have already done in the past,) but also swop out your keyboard…for a known good working one with a PS2 connection
2 Run chkdsk /r from the start run, accept the warning and let it run on restart you need 2 consecutive runs with no problems found in all 5 passes before this is OK (keep running it until you achieve that).
3 I assume you have run memtest…if not let it run overnight
http://www.memtest86.com/download.html
4 change your hard drive cable for a known good working one and disconnect your optical drive cable and Internet connection (physically pull the plug)
5 Reset BIOS to default and see how you go
6 Finally before you strip it all down and have the mobo running on the bench (removed from the case) to rule out any shorting…download on another machine a live distro of Linux
7 Live versions will run from memory and the CD and do not need to access the hard drive………available from here:
http://www.linux.org/dist/ …If you are not into Linux then get the latest Live version of Ubuntu available from here:
http://www.ubuntu.com/ This is practically the same as Win XP , but just so much better!…………:if you can't run Linux from a live CD then it's definitely hardware and a strip down of your mobo, re seating RAM re seating CPU + heatsink and new thermal paste, checking capacitors for bulging tops and any fluid leakage, swopping out the PSU etc will be needed before you contemplate the next step
8 if you have a mobo tester then try it…….if you don't have one try and borrow one from your friendly neighbourhood computer technician…or as a last resort have a look on eBay for one as some cheap imported ones sometimes work quite well and are pretty inexpensive now.
Let us know how you get on…but this lot should keep you busy over Christmas!
Regards
paws