Automatic shutdowns and reboots. Can't stay on for more than 15 minute

[Rorym865]

Recently, my PC has been shutting itself down (as in powering down) and rebooting seconds later. This started out at random times, both in use and completely idle, but it's got progressively more frequent to the point where my PC can now no longer stay on for more than 10 minutes, sometimes shutting off before I even get a chance to log in. I've been intensively and ultimately hopelessly troubleshooting for days now. Here's a list of what I have discovered:

I've replaced my PSU.
I've checked for overheating and even replaced the CPU cooler.
I've run memtest86 and all tests were passed.
I've unplugged all nonessential hardware.
I've plugged the PC into a different power socket.
I've run DSKCHK.
I attempted to run two virus scanners from booting them from CDs, but my PC shut down, although it was fine for the memtest, and stayed on for an hour in the BIOS settings without shutting off.
I used the command prompt on the Windows 7 disk to scan for errors. None found.
I've switched out my mouse and keyboard.

Despite all of the above, the problem still persists. However, my system APPEARS to run fine in safe mode.

Anybody got any thoughts at all?

 

[Pauly]

My initial thoughts would be overheating, I know you have changed your cooler but have you actually monitored temperatures from power up to a reboot to see if they are progressively rising ?
If it is an overheating issue then you would expect power up time to be at its best following a cold boot decreasing after reboot as machine is already warm

Check event viewer and see if you can get any clues as to why the machine is shutting, check for errors immediately prior to a shutdown

 

[Rorym865]

My initial thoughts would be overheating, I know you have changed your cooler but have you actually monitored temperatures from power up to a reboot to see if they are progressively rising ?
If it is an overheating issue then you would expect power up time to be at its best following a cold boot decreasing after reboot as machine is already warm

Check event viewer and see if you can get any clues as to why the machine is shutting, check for errors immediately prior to a shutdown

Sorry, yeah I've made sure to monitor temperatures and my CPU and GPU never exceed 50 degrees Celcius. They have been known to get into the low 80s while gaming, but my PC never shuts down during gaming since I've not even had the chance.

 

[Pauly]

Check event viewer see what you can find

Is the machine performing a controlled shutdown or is it hard crashing to a reboot

 

[Rorym865]

Check event viewer see what you can find

Is the machine performing a controlled shutdown or is it hard crashing to a reboot

Last time I checked event viewer all I could find was the usual 'the last shutdown at x time was unexpected'. I'll check it again when I next get the chance and post my findings.

As for the rebooting, the PC is literally powering off as if the power has been pulled, and powering back on again seconds later.

Another thing I forgot to mention was that I have disabled automatic restarts when fatal errors occur, but it still does this.

 

[whs]

For a test, run a live Linux CD for a while. If that stays up, we know the hardware is not at fault and we narrowed it down to a Windows problem. If Linux does not stay up either, then it would be a hardware problem.

If you have no Linux handy, make yourself a little kit like this. Then boot from the USB.

http://www.sevenforums.com/tutorials/287439-emergency-kit-save-your-files-dead-os.html

PS - that kit may be handy at other times too.

 

[Rorym865]

For a test, run a live Linux CD for a while. If that stays up, we know the hardware is not at fault and we narrowed it down to a Windows problem. If Linux does not stay up either, then it would be a hardware problem.

If you have no Linux handy, make yourself a little kit like this. Then boot from the USB.

http://www.sevenforums.com/tutorials/287439-emergency-kit-save-your-files-dead-os.html

PS - that kit may be handy at other times too.

Thanks, I'll try this when I can. If it helps however, I already tried using Kaspersky Rescue disk, and it shut down during use of that. However it didn't shut down during memtest86, which was purely text-based, and I left the BIOS settings open for an hour without a shutdown.

 

[whs]

So you have actually 2 different test results. The Kaspersky would suggest a hardware problem and the memtest would suggest a software problem.

I think you need a third opinion.

 

[Rorym865]

So you have actually 2 different test results. The Kaspersky would suggest a hardware problem and the memtest would suggest a software problem.

I think you need a third opinion.

Well safe mode seems to run fine, which is what's been baffling me.

 

[whs]

That would suggest that there is no hardware problem. Go to msconfig and disable the startups, then reboot. If that works well, then there is a startup culprit.

If not, same procedure with the services.

If you found that there is something wrong with either the startups or the services, then you have to run them in small groups to narrow the culprit down.

 

[gregrocker]

If the PC runs fine in Safe Mode then the issue is likely a driver. Check System Recovery Options if you have a System Restore point from before the problem began as Windows Update may have delivered a problem update or driver.

If not while I Safe Mode try as many of the Troubleshooting Steps for Windows 7 as possible as these may reveal the problem. I'd first establish a Clean Boot, uninstall and change to one of the recommended lightweight AV's which never give problems, disable that strange Sound card driver to see what happens. Then scour the logs and other system resources suggested.

But I think I would not waste much time before I deleted all partitions during a booted install to Clean Reinstall Windows 7 sticking with those steps which have been used by over a million consumers to achieve a perfect install without a single complaint, or anyone returning with any issues who stick with the tools and methods given.

 

[cluberti]

Also, this:

How to stop Windows 7 automatically installing drivers

Keep WU / MU from installing drivers and driver updates, ever. This is one place you should review and do on your own if possible.

 

[Rorym865]

That would suggest that there is no hardware problem. Go to msconfig and disable the startups, then reboot. If that works well, then there is a startup culprit.

If not, same procedure with the services.

If you found that there is something wrong with either the startups or the services, then you have to run them in small groups to narrow the culprit down.

Just tried this to no avail. The only logical explanation I can see left now is my GPU itself or my graphics drivers. Is there any way to narrow it down to this for certain?

 

[whs]

You could run a GPU stress test.

FurMark: VGA Stress Test, Graphics Card and GPU Stability Test, Burn-in Test, OpenGL Benchmark and GPU Temperature | oZone3D.Net

 

[Rorym865]

You could run a GPU stress test.

FurMark: VGA Stress Test, Graphics Card and GPU Stability Test, Burn-in Test, OpenGL Benchmark and GPU Temperature | oZone3D.Net

Impossible. My PC doesn't stay on for long enough in normal mode.

 

[whs]

Try in safe mode.

 

[Rorym865]

Aren't graphics drivers bypassed in safe mode?

 

[Pauly]

Yes they are, windows drops back to basic inbuilt vga driver
You could uninstall gfx driver and run basic gfx in normal operation to see how it goes

 

[Rorym865]

Yes they are, windows drops back to basic inbuilt vga driver
You could uninstall gfx driver and run basic gfx in normal operation to see how it goes

I'll give that a try tomorrow.

 

[whs]

Aren't graphics drivers bypassed in safe mode?

Yeah, but that's a program that will test it anyhow.