Hi, I have a desktop running the following:

WinXP SP3 (pretty sure)
AMD Athlon XP, not overclocked
ASUS A7N8X-X mobo
Antec True 380W
1gb ram
ATI Radeon 9800 pro

I built it myself about 6 years but haven't really been updating parts or anything, just made a few random add-ons (ram, a 5.1 PCI sound card)

Now my problem: for the past, maybe 2 years, I've had this problem where the desktop would restart a few times before actually booting up to windows. But never did it just flat out shut down on me. Today, it just died after a few seconds. One try it died after getting to the windows log-on screen. Another time it died after a few seconds of loading. I had a thought it might've been a hardware problem before, but b/c everything else ran fine, I didn't bother pursuing the problem. Now it doesn't even load properly and I don't know where to start. Any advice?? Thanks in advance!

Any hardware failure would normally cause the BIOS to make beep noises other than the normal single, short beep.
Are you getting unusual beeps from the BIOS during booting?

If no unusual beeps, the problem could be software or OS related.
Tap F8 as soon as PC is powered up. This should bring up the 'Advanced Startup Options'
Highlight "Last known good configuration" with arrow keys and press [Enter]

most likely canidates would be overheating or dying power supply.... could also be the motherboard or the video card but check the above first.

The beeps weren't to irregular... I don't think, nothing that I remember. As for last known config, I did try that before when it did the whole, "restarting a few times before actually loading windows", but it didn't change that.

However, recently, b/c I have a thermaltake heatsink with variable fan speed, I tried turning up the fan speed and surprisingly the computer is booting normally now. Could this mean that my heatsink was just too slow for my processor? Also, how do I check my powersupply's condition?

sounds like it was just overheating... you can get a power supply tester but not all of those give a good long test, you could also check the bios for voltage levels.... they should all be within 5-10% of the listed value. They should also stay relatively stable....

Could you give a little more detailed directions on how I would go about that? Thanks.

Turning up the fan on the CPU allowed more air to circulate.
What is the condition of the fan/ heatsink?
Try cleaning the dust and cobwebs off the fan/ heatsink.
Clean all your fans. Do this with the computer off and unplugged.

You can get Everest (from my signature). Everest will give you the temperatures and voltages.

Another seemingly strange problem I have discovered... When my room is relatively cold, (like maybe 50F?), the computer will also not boot up. It still does the, shutdown after a one or two attempts at loading winxp. When I warm the room up to about room temp or higher, the computer will boot up fine. What does this sound like? Thanks in advance!

Hmmm. This could be bad capacitors, temperature dependent sucess. Unfortuantely, failure when cold but not when heated is also a sign of a cold solder joint. Which when the metal contracts (cold) fails, when it expands (warm) it works.

I would FIRST look for bad capacitors around the motherboard (look for bulging or leaking capacitors, they will bulge from the top), also look for bad brands such as Teapo, GSC, Fuhjyyu, Evercon, Rulycon (not to be confused with RUBYCON which is a top line capacitor).

Also, if none of these are the issue, I would look at reseating your heatsink. It may be marginally contacting the processor, though this is more of just throwing it out there.

The capacitors look fine; since the mobo is made from ASUS, I at least don't think they're bad quality. Is there a program or something that I can use to see if my processor temp is the problem? I haven't had a chance yet to check out the power supply but i'll try to do that asap. Thanks guys!

Doning some searches, I am seeing some posts about this particular motherboard having a southbridge chip that overheats causing lockups and data corruption (the south bridge often controls the flow of data to and from the hard drive). You may try putting a heatsink on the south bridge (if it doesn't have one already, if it does aim a fan solely at that chip and see if it helps your boot up I saw reports of this helping).

Oh yeah, ASUS is well known for using crap capacitors at times (some boards are full of them others are full of great ones, no correlation to price point either which is odd).

This post has been edited by PedroDaGR8: Dec 1 2008, 09:05 PM

Ok I just cleaned out all the dust/cobwebs/whatever from the computer and I tried turning on the desktop today and now it's making the irregular beeps. One about every 3 seconds, there's a drawn out (about 1 second long) beep and it just keeps beeping w/o loading any screens. So obviously some hardware isn't working right? I really hope I don't have to go shopping for many new parts...

Based on the beep code, it appears it is either the ram or the video card ( I found two different replies online, you may want to check your manual to see if it lists the values for the beep codes or contact asus support and see if they will tell you). That being said an easy program to test your ram is to use the program Memtest86+. Download and burn it to a cd, it will be a bootable CD, so place it in the drive and restart your computer and get it to boot from the CD. Let it run for 12hrs or more, I let it run for 24 hrs. If you get more than 1 or 2 errors then your ram subsystem is suspect (I usually get none, but occasionally you will get one or two from interactions with cosmic radiation, surprisingly enough).

Also, try resetting your videocard and see if that helps.

This post has been edited by PedroDaGR8: Dec 1 2008, 11:02 PM

Ok, funny thing. I remember taking out my ram just to see what kind i had yesterday, so just now, I reseated them, and booted up my computer and it works now... It asked to set my cpu speed, so i just chose the lowest (100mhz) for now. Should I run the memtest now through windows? What other tests should I run... powersupply?

Memtest is run from a disk because windows holds large swaths of ram in reserve, ram it then can't test. I would test it just to be safe. I would run memtest first. You can download memtest here. They come as precompiled iso's for burning a cd or loading to a floppy disk. Either way, boot from the disk you create and let it run. Thats it. Just let it run for 12+ hrs and see what if any errors come up. If no errors come up and the weird problems keep appearing then we will start looking at the power supply.