Hi, I found good specs here, so decided to ask about my girlfiends PC.
It is quite old about 4 years. It was complected with:
256 MB RAM Kingstone DDR333
80GB HDD
AMD Athlon XP about 1,7 GHz
CD-ROM
Win XP Pro
I added extra 250GB HDD, DVD-ROM and after a month a 1GB RAM DDR400 A-data
When added extra memory, PC started to reboot without bluescreen. No matter, what am I doing - playing online games or writing Word document. No special things doing on PC. I thought at first it's the memory, who makes it reboot, so I changed it with a 1GB Kingstone DDR400, no changes. I removed the 256MB RAM, the same.. Reboot after a while.. I replaced it with a 512 RAM of my PC, a bit rare rebooting, but still not good. I changed in BIOS from DDR400 to DDR333, a bit more rare reboot, but still it reboots.. Sometimes 4 times in 1 hour, sometimes few times a week. I changed motherboard with bether one.. the reboot now is more frequently. So, what could be the broblem? HDD and RAM errors should be with bluescreen, maybe it's the Power suply? Maybe due to PC upgrade (RAM 2x more) the system needs more power to suply new resources of it?
Thanks!
Sorry for my english!

If it's not a Hard Drive problem, I wouldn't know what the problem is. Maybe another forum that deals with general computer repair might help.

Bad power supply can cause computerr to reboot.

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www.datarecoveryne.com

system properties>advanced>startup and recovery>settings>uncheck automatically restart

now you'll get the bsod you so desire

get the ubcd iso
run memtest

test the power supply.
could be heat, check the heat sink(s) make sure the fans are working.

Check for minidump files....

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Buy your friends Toshiba\Hitachi and your enemies Seagate.

Auto reboot has been disabled! I checked RAM with memtest (ubuntu live cd), no errors found.. The same RAM running good on my PC. How many W should i need for my Power Supply? Have not complected PCs for years, so have forgot many characteristics of PC.

Fans are working.. CPU temperature is normal, PSU looks fine from inside, looks like the temperature is normal too.. But does the PSU warm up, if it can't supply enough power?

OK, I lied. Was hoping to keep things on topic. Anyway....

Forget wattage on the PS. Unless if you are a hard-core gamer, or have 5 drives, it likely doesn't matter. What matters is quality. A cheap 500W power supply is often a relabeled as a cheap 300W power supply. You are MUCH better off with even a good 250W. Cheap supplies tend to put out more ripple, and are more likely to not be at the proper voltage, both of which can cause crashes. Also, cheap supplies like to skip overvoltage protection, which means you'll be back here eventually with a "My hard drive PCB burned, how can I get my data?" kind of question.
Even a good brand of PS can cause crashes, especially if it's old. The capacitors used dry out and lose capacity over time. This increases ripple.

In short, if you've already checked everything, replace the PS with a good one.

i had one like this not long ago, ended up being CPU...we changed amd cpu..i think it was 2600.. and fixed it in the end...we tried powersupply and ram 1st

_________________
Buy your friends Toshiba\Hitachi and your enemies Seagate.

Changed the Power Supply with "FORTRON CASE PSU ATX 350W 12CM/ATX-350PNF RO" ( http://m79.lv/product/single/group/77/v ... _350PNF_RO ) for about 28.33 USD, everything works just perfect. No reboot now for 3 days. Running with 1GB Patriot RAM that previously killed boot sector of WIN XP because of reboot in 2-10 secs. Now planing to add more memory http://m79.lv/product/single/group/24/v ... _3__RETAIL ..
Thanks for help!

Glad it worked out. Fortron is usually a good quality low cost PS.