please HELP! windows xp keeps rebooting

[remixer999]

I've been running windows xp on my computer for about 8 months now with no problems. I have a amd athlon 64 3000, 1 gig kingston 3400 ram, bfg 6800gt video card, 160gb sata hd. Windows starts up, gets to the windows splash screen with the bar moving across while it loads, goes black, then reboots. This is an endless cycle. I can go into safe mode, which i did, to back up all my important documents and files. I really don't want to reinstall windows again so is there any other way to fix this problem?

I believe the last time it was working was before I went on a trip for 3 days, left my computer on while it was downloading something, and came back to see my monitor black and not turning on. So i just turned off my computer and turned it back on, and that's when it started. I first thought it was a hardware problem, sent in my video card to get a new one, same problem. Ram is fine too, and didn't test my hd on another computer just yet. Any help would be greatly appreciated.

[mumber]

Buy another monitor.

[Whyzman]

You can set XP not to reboot but rather show the error message.

[ErnieK]

Right click My Computer
advanced
Startup Recovery (at bottom) Setting
Now DESELECT AUOTO START.
Reboot computer to ensure new settings.

Next time the error occurs you should see the error number. Write it down and post back with the details for possible help.

[Sylvander]

What changed just before this began?
STRATEGIES
[I think it's a software problem]
1. If you have a recent good backup of C: [reformat C: if necessary and] restore that to "jump back".
If it's a software problem this will fix it; if it doesn't fix it you know it's not a software problem.
If you don't have a system of backup, then learn from this experience and set up a backup system in the future.
When you do:
a) keep C: small by holding only "Windows" & "Program Files".
b) Move "My Documents", emails, address book, favourites etc off C: so that when you "jump back" these are untouched and up-to-the-minute.

2. Run a "repair" reinstallation of Windows to try to fix any Windows software problems.

3. Use the "msconfig->Startup" tab to untick [except the few necessary ones] all startup processes.
If this ends the problem, "re-enable by halves" to home in on [identify] the culprit that is causing the problem. Then figure out what to do with it.

[Paleo Pete]

Heat and weak power supply are always the first two things to check when a computer reboots by itself, and just long enough for Windows to load is about right for the CPU to overheat and shut down. I have one sitting here on the bench with a fresh batch of thermal compound for exactly that reason.

To find out, first thing to do is open the case and blow all the dust out with some canned compressed air, available at department or office supply retailers. Pay close attention to the CPU heatsink fins, get all the dust and lint you can out of there. Then plug everything up and run it with a small fan blowing inside the case. (leave the side cover off) If it does not reboot, you have a heat problem, either the CPU getting hot or not enough airflow.

CPU overheating:
Replace the thermal pad or compound with fresh thermal compound. Use a thin layer only, too much is worse than none. Clean the old compound off before replacing it with lighter fluid, follow with 90% rubbing alcohol which removes all oils and leaves no residue. Use lint free cloth if possible and don't touch the CPU or heatsink after cleaning. The thermal pad can be scraped mostly off with something like a credit card or plastic bay cover off a computer. DO NOT use metal objects, like screwdrivers, knives or paint scrapers. Those will scratch the surface of the heatsink and leave raised areas which make your heat problem a lot worse because the heatsink and CPU have no contact except on those raised ridges.

Airflow: Add another case fan, preferably in back pushing air OUT of the case. Move the IDE cables and power cables out of the way as much as possible, I try to tuck IDE cables into an empty drive bay and tie-wrap unused power cables into a small bundle which is then tie-wrapped to the top section of the case behind the CD ROM drives. IF your computer usually sits in a desk with a cubbyhole for it, leave the door open if it has one and consider cutting a section out of the back for better airflow. Something about 6" x 6' at the height of the power supply should be sufficient, or a bit taller to allow for a secondary case fan.

If it seems not to be heat, the next thing to check is your power supply. The easiest method is to swap it temporarily with a known good power supply, but I realize not many typical home users have one sitting around to troubleshoot with. In that case probably the best bet would be to take the power supply to a reputable computer shop and have them test it. If you know how to use a multimeter you can check the voltages, but again that's not something a lot of typical home users have experience with. If you can, or have a friend who is familiar with electronics, let us know and we can locate links to the proper voltages, a standard multimeter will tell you whether the power supply is weak or not.

I'm leaning toward heat, if the computer is only 8 months old I would really be surprised if the power supply had already gotten weak, even cheap ones usually last at least 2 years.

[Paul Komski]

The repetitive reboot problem at startup can often be solved by running a repair installation. The fact that things work OK in safe mode would make this even more likely to be successful.

http://www.michaelstevenstech.com/XPrepairinstall.htm