Why is my PC shutting down randomly?

March 27, 2009 4:58 PM

My desktop PC is powering down overnight randomly and I can't figure out why. Windows XP Pro SP3.

The power options are set to shut off the monitor after 20 minutes, but never to shut off, standby or hibernate. I have turned off automatic updates (it was downloading windows updates and then restarting, so I shut off the auto-updates, and now it's just shutting down without restarting).

I'm not sure what other info is relevant, so I'll try to watch the thread. I only use the desktop every few days, so I'll come back to it after a day and it will have shut down. But sometimes not. It never does this while I'm using it. Nothing else is funky. It's almost exclusively used for web surfing, iTunes and utorrent. It's on a network with other computers in the house (that don't have this problem). Virus and spyware scans are clean.

posted by desjardins to computers & internet (21 comments total)

Is it actually shutting down? My desktop (SP3 as well) keeps randomly powering down, but actually hibernates, complete with the restoration screen when I turn it back on. I can't figure out why, either.
posted by niles at 5:03 PM on March 27

Maybe you have a heat issue? Do the vents have sufficient clearance around them. Any dust buildup around your vents that would impede airflow?
posted by Craig at 5:05 PM on March 27

Check the power supply.
posted by leafxor at 5:12 PM on March 27

niles, it's not hibernating - when I push the power button, it boots up from the starting point.

Craig, I will check the dust situation. The vents are not impeded in any way and the room is cool. The case does not feel warm (been using it for about an hour now - not sure if that's long enough to be significant).
posted by desjardins at 5:14 PM on March 27

Have you anything set to "Shut down when X completes?" That could be downloads, ripping, email, anything. I had a problem similar and the cause was the accidental enabling of Outlooks useless "Power down after checking mail" feature.
posted by fire&wings at 5:14 PM on March 27

leafxor, can you be more specific? What exactly am I looking for?
posted by desjardins at 5:15 PM on March 27

I don't use outlook. Literally, I use Firefox, iTunes, uTorrent (and I disable "power down after downloading" on that) and sometimes VLC. I had Office 2007 installed recently but I have not used it yet.
posted by desjardins at 5:21 PM on March 27

Is there anything relevant, just prior to the shutdowns, in the Windows Event Log? (Start > Run > eventvwr.msc). The event log would at least tell you if the shutdowns are happening randomly or at a regular time.
posted by matthewr at 5:27 PM on March 27

Hi desjardins, I would check your Event Viewer first within Windows and see if any thing odd (errors, faults, etc) are happening overnight. You can access Event Viewer by right-clicking on My Computer and choosing "manage." A Computer Management window will come up. There will be different categories of logs (system, application, etc.) - take a browse through there (probably starting with system) and see if there are any logs that reference a shutdown. It might be proceeded by a log for a fault or error (with a red exclamation) or the logs might be one in the same (the error combined with the shutdown.)

It's something to check.

Are you using utorrent to download torrents at night? Sometimes torrent programs have a "shutdown computer after download completes" option and that might be checked. You might also check your antimalware applications to see if they are turning the computer off overnight after scans.

Do you have any tasks schedule for overnight in Task Scheduler? Maybe something set a scheduled task without you knowing? Something else to check.

Just some ideas I thought of. Good luck!
posted by karizma at 5:29 PM on March 27

nthing the power supply comment, I used to have a computer where the power would cut out semi-randomly which later escalated into not booting unless it was unplugged for a few minutes. Turned out to be the power supply.
posted by TimeDoctor at 5:30 PM on March 27

Oh, and my apologies for some poor grammar above - I am in a hurry :)
posted by karizma at 5:30 PM on March 27

leafxor, can you be more specific? What exactly am I looking for?

Run your computer, and get a temperature monitor. If your PSU has a temperature sensor, post graphs of that (you can use Everest Home).

Check Windows Event logs.
posted by leafxor at 5:33 PM on March 27

See if there are power options in the BIOS that aren't to your liking.

Or, shut the thing off when you aren't using it. If you hibernate it, it will reboot fairly instantly and you'll save a lot of money on electricity.
posted by gjc at 5:41 PM on March 27

OK, checked event logs, and here is the last thing that happened before shutdown last night. [screenshot] [event log screenshot]

wtf is prisoner.iana.org ?
posted by desjardins at 5:49 PM on March 27

The vents are not impeded in any way and the room is cool.

It's worth taking a look inside to check that the CPU heatsink isn't clogged with dust and that the CPU fan is still spinning.
posted by We had a deal, Kyle at 5:52 PM on March 27

OK, I could have googled that myself, but honestly I'm not sure what this all says, or if it relates to the shutdown issue.
posted by desjardins at 5:56 PM on March 27

My XP SP2 was shutting down randomly but it didn't seem that dusty either.

Then I opened up the damn thing. Oh, my.

If you have had the computer for a while and have never cleaned it, especially if you work in a room where the window stays open for any length of time, you may have a lot more dust than you think. Unplug the power supply, get the vacuum cleaner and a soft brush attachment out, and be gentle and thorough. You'll need a small, soft paintbrush, too, for some of the more delicate parts.
posted by maudlin at 6:00 PM on March 27

OK, OK, I get the hint. I promise to dust the thing out tonight. :) If that's what causing it, I will buy you beers/coffees when you come to Chicago.
posted by desjardins at 6:03 PM on March 27

The prisoner.iana.org entry is a furphy - ignore it, it's not relevant.

Basically, most versions of Windows by default try to register their local network with IANA (the Internet Assigned Names Authority), even when it's one of the non-routable networks assigned for local use (e.g. 10.x.x.x, 192.168.x.x, etc). Back in the dim dark days, IANA realised they needed 'placeholder' servers to deal with this, and prisoner.iana.org is the IANA server for 192.168.x.x.

Basically, Windows is trying to say "I'm the DNS server for 192.168.1.1", and prisoner.iana.org is saying "Yeah, OK - now go away" ;-)

To pile on to everyone else's suggestions, every time I've seen unexplained shutdowns with no relevant entries in the event log it's been one of four things - heat, bad PSU, or dying motherboard are the first 3, and automatic wakeup/shutdown settings in the BIOS without ACPI also being enabled is the fourth.
posted by Pinback at 8:22 PM on March 27

When you open it make sure to spray between the fins on the CPU heatsink. On some designs the fins were just enough apart to be great dust collectors.

You can look at your temps right now using SpeedFan. Maybe you should take note of your temps before and after the cleaning. If they stay the same then you probably have a ps or motherboard issue.
posted by damn dirty ape at 8:41 PM on March 27

I know it's a desktop, but there's an *outside* possibility that some 3rd party software changed your power management settings.

Control Panel -> Power Options; check the settings in all the tabs and make sure that there aren't any shutdown options listed.
posted by porpoise at 9:39 PM on March 27