This puter has turned into a nightmare. It has a MSI 745 ULTRA AMD 1100 with AMI BIOS. Its older but plenty for a 10 year old gamer. I have tried everything i know. I have a Vaio loaded with toys and have gone as far as to pull out mem an video to test compatibility with this 1. I have also swapped out mem , cdrom, and 2 other video cards i have, replaced connecting cables/wires with known good ones, unhooked all devices, cleaned all dust, an replaced cmos battery. This is what i have...(This situation never repeats at the same time) sometimes windows loads an seems fine until i start loadin something or surf and then it restarts. Sometimes it doesnt make it past BIOS before it restarts. I do get a beep code (single beep) which for this i believe is bad MEMORY but i have tried several known 2 be good mems. Honestly it seemed to be running fine and i wasn't gettin any beep code before i started updating to service pack 3 (which was the 1st crash) but now i cant keep it runnin long enough to reformat. Personally i dont think its the update but im no expert. I have an old Sidewinder force feedback pro and other gadgets and have this cool gaming setup i was doing for him for his birthday and this has become so frustrating. Any help would be much appreciated. I would travel to Crucial's website enter the specs and see exactly what type of RAM that machine uses and then shop around for the best price...
You should get lucky...RAM is a real bargain right now.Tried another power supply? Disconnect all unnecessary hardware, remove all but one stick of memory. Gradually add more hardware if you find the machine's reliability has improved.

If you get blue screens, the stop code and any drivers MENTIONED would be very helpful in tracking down the problem.
To ensure you get time to read a BSOD screen, follow these steps;

Go to Start -> Control Panel -> System
Go to Advanced
Under the Startup and Recovery section, click SETTINGS...
Under System Failure un-check "Automatically restart" Yea, already did all this. Even tried different power supply. Thanx for the reply but as stated i have installed memory known to be good. All of a sudden it seemed stable for about 30 min and then restarted and now im getting different codes. Sometimes when it restarts it beeps once and sometimes twice. Single beep codes on this bios suggest bad mem but im replacing with known "good" mem, does this leave me with a bad motherboard or is there any other possibilities?It sounds quite like something up with the board itself given your reply.

What happens if you remove everything except CPU - take out all memory, leave graphics card in, switch on and check for beep codes, then take out the graphics card too - you ought to get suitable beep codes warning of lack of memory, lack of VGA etc...

"Sometimes it doesnt make it past BIOS before it restarts." - that is definitely a bad sign...

You said you replaced the CMOS battery, have you reset the BIOS to fail-safe defaults, or did you clear CMOS memory anyway?earlier when i removed graph card i got normal beep for that, what seemed odd to me was when i removed memory i recieved no beeps, at all. the puter just sat there, no nothing. Is this normal? I thought bios would load even without mem.thanx 4 every1s response. i finally pulled the main board, reseated the processor, reinstalled main, cleaned all connections, and hooked it all back up. Its runnin! I got a few blue screens when i tried updating the bios or windows so im just leavin it alone. Its runnin games and can surf so its good enough. He came home and is blown away. I have the whole "gamers" setup for him, he couldn't be happier. 1 thing though...microsoft never made any drivers for the force feedback pro for windows xp so it doesnt feedback like it did with 98. does any1 know if there is a driver out there that will run it like it use to be? I have always been blown away that micro didnt make compatible driver updates, its an awesome game controller.