I have a computer here that seems to restart itself for no apparent reason. I took a look inside and see that the motherboard's capacitors are a little swollen on some of them. So I replaced the motherboard. There recently was a power surge in the area, so I also replaced the power supply. I thought that would fix the problem, but the next thing I know, it restarted again. This time it restarted at the login screen.

Is it possible that a network could cause this issue? I looked at the back of this computer and see that the network port has one solid red light and then a blinking orange. It was giving her problems logging in before. So I just shut it down and then started looking at the back and jiggling the ethernet cable to see if the light would turn green. While doing that, I noticed that the monitor blinked...basically the computer just restarted at the login window. This computer is connected to a hub/switch which is connected to the network (wall jack). The strange thing is that I could login and go online even when the network ports light is solid red and blinking orange. I don't think this is normal though...should be green

What could be causing this? I'm thinking hard drive now since I ran a memory test and it passed without any errors found.

Thanks.

What version of Windows is it?

I've had Windows computers reboot for no reason at all but upon closer inspection, a BSOD (blue screen) was quickly shown.

Also, I'm a little confused. I've never seen any Ethernet adapter have any other lights besides a link light and an activity light, both being green. Is the ethernet built right into the motherboard?

[N]F

It could be a driver problem, I've had windows restart for no apparent reason and eventually I tracked it down to a bad driver. Please let us know what version of windows you have, and if your running 2k or XP jump into your control panel/Administrative Tools/Event Viewer right after a reboot and check the system section and see if it gives a yellow warning or red warning and the software section and see if you have a yellow warning or red warning and tell us what error is being given.

We will be able to help you out better if we have that info.

This might not be an issue of software at all. Yes I know it is a pain in the but when you're busy working on a document and all of a sudden the PC restarts itself.

I have run into the problem three times in the past with different computers and the solutions was hardware replacement in all cases.

If you have blown caps on your motherboard then the motherboard will have to be replaced. (Hopefully it is still under warranty.)

Generally there is a cause for blown caps which is some other piece of hardware that is faulty. In two of the three examples that I mentioend above, it was the power supply. Good news is that power supplies are not only cheap, but they're easy to install. We were able to upgrade the strength of each PS to a higher wattage, and the problem went away.

Not having examined your PC I can't say what the cause is, in your situation ... but if it was me, I would look at hardware first.

A word of warning ... if your PC restarts at a moment when your OS is writing to your hard drive it can corrupt your OS. This has happend to me twice. The entire system had to be reinstalled.

I know what you mean ... not uncommon at all!

Usually whenever something like this happens (continous reboots), the first thing I do is backup MyDocuments, C Drive and any saved files in PrgoramFiles and do a format and reinstall. That's easier than cleaning any dam virus or problem in the system and takes much less to do. Of course this has never been a problem because there's only one user account.



That usually is a hardware problem, and not unfrequently the RAM.

But in this case, since the RAM is fine, I'm inclined to think it's the Hard disk. Try this:

1. Go into the recovery console using the Windows XP CD.
2. Select the Partition in which windows is installed.
3. Type 'chkdsk /p /r c:' assuming windows is installed in C drive, else substitute with another letter.
4. Better to do it for all the partitions, just in case.

Then try starting windows. My friend had a problem like this and this kinda fixed it. Of course his system kept giving a 'UNMOUNTABLE_BOOT_VOLUME' BSOD.

actually, it is a Windows error and due to a network mishap. I run several Windows machines, whenever one Windows machine sends a bad packet to another Windows machine when sharing files, it'll kill the host machine. Thus, Windows will reboot. This error was fixed by the Samba project that allows all UNIX machine to connect with the Windows network.

xboxrulz

Sorry about that...thought I did mention the version. It's using Windows XP Pro. It's a Dell Optiplex GX270 machine and the ethernet is built-in to the motherboard. The red and orange light is definitely making me scratch my head. So that's why I'm wondering if it could cause that...

I changed the motherboard and power supply already for her. I thought it was a simple task to do since I got both of them on hand already before I went and noticed the blown caps. But after one or two restart when I was testing it, it restarted itself at the login window (I was checking the back of the computer at the time so it wasn't logging in). Next thing I knew when it restarted, I logged in and it said something about the registry being corrupt...I just clicked ok and it repaired itself. Didn't show up again after another restart. She said it can restart any time (like you guys said earlier...even in the middle of a Word document). Only thing I can think of is hard drive now. Are there any tools that I can run to test out the hard drive's integrity?

abhiram, for the UNMOUNTABLE_BOOT_VOLUME message, can chkdsk really fix that issue? I didn't take my chances last time and just replaced the hard drive for another user. I will try using chkdsk on this hard drive and see how it works. Bringing another hard drive just to be safe.

xboxrulz, how would I fix this then? There is a hub or switch that the computer is connected to. From that hub/switch, it's connected directly to the LAN.

I'm returning to check on that computer on Tuesday. Will look at the Event Viewer and see what I can dig up there. Already told the user to backup her data as soon as possible.

Many thanks for the replies

UNMOUNTABLE_BOOT_VOLUME can't be fixed, I've tried many methods already. Ironically, my good friend just ran into that error... interesting... actually, I'm still in the middle of solving the network mystery, now I have to go back and research on the UNMOUNTABLE_BOOT_VOLUME. In both events, I believe it has been from a network issue as my friend didn't touch her computer and when she came back, her machine crashed with the BSoD with this error. Also, about the issue I said on the earlier post, that machine also rebooted, but never showed a BSoD.

For me, to fix my friend's machine, I completely reinstalled her Windows over the old one. However, the UNMOUNTABLE_BOOT_VOLUME sounds like the partition has been locked down by Windows because of a serious error, try booting a "Ultimate Boot CD" (http://ultimatebootcd.com/) It is also best for you to download the original version of the UBCD and not its Windows spinoff. Then, change the partition setting to Active and Bootable.

I'll have to go back to the drawing board again...

Thanks for your report.

*PS: You're lucky, I'm on my summer vacation, so I have more time to investigate on this problem, I still have to figure this out for my friend anyways and I'll handle this under Software Investigation priority*

xboxrulz

This post has been edited by xboxrulz: Jul 9 2006, 04:30 AM

My friend gets the UNMOUNTABLE_BOOT_VOLUME error once in every 2 months or so and he kept getting it even after his first hard disk crashed and he got himself a new hard disk. Everytime it happens I tell him to go into the recovery console and run the CHKDSK /P /R command for every drive. It worked for him everytime. In fact, it worked quite well for others also to whom I suggested this method.

My guess is that UNMOUNTABLE_BOOT_VOLUME comes up because some partition gets corrupted. By running CHKDSK /P /R it forces a check and automatically repairs all errors detected. The next time it happens, try it out, it's always worked for me before.

I'll try that... but I've also noticed something, this is a short report I wrote last night:

UNMOUNTABLE_BOOT_VOLUME
- affects Windows 2k+
- affects networked machines
- involves hubs and router
- users claim to see the UNMOUNTABLE_BOOT_VOLUME error
- involves UNPROVOKED shutdowns or reboots
- all cases involves users not touching the machine and used network-enabled software.
- UNBOOTABLE_BOOT_VOLUME --> Windows may have locked the parition to prevent ANY damage.
- Definition of the error also suggest that either the O/S cannot unmount the Boot Device or the O/S couldn't even mount the device.

Those are my findings.

xboxrulz