Computers instantly restarting during gameplay...

I have a problem where in some games playing for a while will automattically restarts my computer(s). One does it in Jedi Outcast and the other does it in diablo 2 lod. I'll be playing then all the sudden the computer will restart. Now, the only conclusion I can come to is a psu problem because I have very weak 300watt hmm maybe 350 i'm to lazy to check. But all my parts in my computer are baught brand new and what not EXCEPT for the OLD psu's. Thats why I think it could be them because I know i've had them for at least 5+ years. Please if you have any insight that would be helpful. Thanks. :)

System 1
AMD Athlon 2400XP
NF7-S
Geforce 4 Ti4800SE
2x256mb Corsair 3200
60 gig Western Digital 7200rpm hd
NEC MultiSync FE771sb
Windows XP Pro

System 2
AMD Athlon 1800XP
Soyo SY-K7ADA
Geforce 3 Ti200
1x512mb ???
20 gig dunno hd?
Old 17" monitor
Windows XP Pro

Do you overclock ?

Probably ram or psu, test the ram in memtest....

In System Propertie>Advanced>Startup & Recovery uncheck Automatically restart
This should hopefully let you see any error messagezs & give you a clu as to the culprit.

well I know for a fact it couldnt be memory because it did it before I got brand new memory... And when the computer restarts I get that "Your computer has blah blah serious error". I look at the details and it says its something with my cpu and I should call somone up blah blah blah. But thats also weird because my CPU is practically brand new. I have 2 1/2 idea... 1st, could be my crappy psu's, 2nd, could be overheating? maybe?, and 2nd 1/2, it might might be cpu but I Highly doubt that. Anyways, any help is extremely kindly accepted.

Thanks!

IT could be ram, it'll course the system to randomly reboot....

Well I just did the "System Propertie>Advanced>Startup & Recovery uncheck Automatically restart" thing and went onto jedi outcast... Just restarted automatically like usual. Anyways, how do I go about doing this memtest thing? Will it fix the problem?

Thx...

Nope it wont fix the problem, but it'll tell you if you have a problem with your ram. Its a very good test, burn it to cd or use a floppy to use it...

http://www.memtest86.com/

If you find you do have alot of errors its ram rma time! Had to rma 2 sticks for a pc I put together for someone a couple of weeks ago. Pc was randomly rebooting / unstable etc..

As Skii asked - are you overclocking?

On the NF7-S i would try upping Vcore slightly.

not overclocking anything what so ever... Vcore? woah woah i'm lost!!!

Oh man oh man.... I tryed to work with that memtest thing and lol I dont understand how to do it one bit. Any help for this now lol would be good. I dont have a floppy either.

Thx...

What's your power supply like?

You need a floppy to run memtest..

I also get that problem when I overclocked above a certain limit (198x2, I didn't bother testing in more details, as much as I would've liked hitting 200x2).

I guess what you might be able to do is to underclock the memory and see how it goes.. If you still have that problem, then its probably something else causing the problem (PSU is a possibility).

no you dont need a floppy its much easyer and quicker to burn it to cd as a bootable disk. iirc memtest86 site has downloadable cd images for burning to cd.

Why does noone EVER say to test in the first few posts. I see prime95 still hasnt been mentioned....

/it could be one of many things and overheating of the nb, graphics or cpu could be some of them. I recommend you buy a decent psu just for the sake of it. Have a look ath teh 450w CWT psus at scan.co.uk

Check the drivers you installed m8 ;)

Check PSU rails are fine, also increase memory voltage, agp voltage and core voltage just to see if that cures it