Windows 7-64 crashing(rebooting) with no BSOD

My win7-64 system crashes and reboots every few days, usually in the middle of the night. I have the system option to not to restart and the similar bios option set, but system reboots anyway. On restart, the familar Event 41 with bugcheck and powerbuttontimestamp set to 0. After manty hours of running standalong Dell diagnostics and memtest+, not hardware errors are reported. I've updated all drivers. Dell replaced memory, power suppy and video card. I'm running out of things to investigate. All help appreciated. msinfo32 screen shot attached.




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Microsoft Community Contributor
I suppose the first question I would ask is the unit plugged in when this happens. Could a low battery be causing the problem. If this is a desktop, of course disregard this.

Is the unit in hibernation or sleep during these events?

If you knew the time was always the same, you might look for something like Windows updates that happen then. I believe the default Windows Update time is 3 am.

Have you made any changes to your power scheme. Have you tried changing to another version for testing?

If you run a command prompt window as Administrator, you can use the powercfg utility that can be very useful in diagnosing sleep type problems. Start running an analysys by typing powercfg -energy After it finishes, copy the file to the desktop to open (or a preview pane in explorer will work). Look for some type of error message, but some things seem to be fairly normal, like USB notices and possibly a wireless.

Powercfg will also show you what might be set to wake the computer or what last woke it. Type powercfg -? to see a list of the possible switches.

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Based on everything you've done, this actually sounds like a hardware stability problem and Dell doesn't allow you to tweak the bios so investigation of that path is limited.

Did you check the events viewer to see if it suggested any clues. If you had a hardware crash I doubt there will be anything there. The computer will typically take a path specified in the bios and your OS has nothing to do with it other than potentially noting an adnormal shutdown and you might not see that as it follows the standard boot progress that will time out after 30sec (or whatever you might have it set to) to a standard startup.

One way to test stability (there are a number of them) is to download and run Prime95 (link). Let it run for several hours (typically overclockers run for 24hr but problems if they exist often occur far sooner than that, the system will crash -- no BSOD -- and restart). Any stable computer should run it without problems and it will do no damage. The program is built to run your system at a full load. If it crashes you have a potential hardware problem. From all the components Dell has change I would guess a motherboard or CPU.

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View attachment energy-report.txt

Saltgrass & Deepow, thank your comments and insights. This is a Dell desktop that is connected to a UPS. I have an option in the bios that says to not to reboot after a power loss, but the system always reloads in spite of that option and the system option to not reboot after a crash. The crashes happen at various times, but always when the system is idle and I am away from it. I’ve tried many different power schemes in a hope of finding a clue to the root cause, all to no real effect. The powercfg –energy provides new area of consideration and I’ve attached energy-report.html, although at this point I’m not sure what I’m looking for.

I have run Prime95 load utility for an hour at a time with no issues as a result. I will run it over night this evening. The system used to even crash while running the Dell standalone diagnostic, but that is not the case since replacing the power supply, memory, disk, and modem. Crashes used to occur nightly, but after replacing the components, the system has stabilized to every couple of days between crashes. Now, I can run the diagnostic all night without a crash. It only crashes not while running Windows 7. I suspect the current problem might be related to the windows environment. I’m thinking now that perhaps there were a couple of problems that have been partially fixed.

I’ve carefully examined the system event log after each crash, and cannot correlate some event happening before the crashes. I haven’t discounted the motherboard/CPU, but I’m afraid Dell will point their finger at the O/S without substantiation that it is hardware related. I’ve been able to get Dell to replace the components listed because I could get it to fail running their standalone diagnostic. But, that is no longer the case. And I hate the idea of reinstalling windows and all the applications, only to find that the problem still occurs.




Excellent Member
Microsoft Community Contributor
You seem to have quite a few USB devices connected to the system, could you unplug any unnecessary ones?

Could the problem be in the UPS? Perhaps try another plug, or bypass it for a while.

Often the stability test fails quickly. The ultimate test I've found to be IntelBurnTest. Whatever test, make sure you're loading all the processor cores.

Regarding Saltgrass' comment, I once debugged a setup for weeks with unexplained crashes. I even bought a new motherboard (well I wanted one anyway). It was a poor connection with the power plug from the PC to the UPS. Wiggle the connect and PC would crash. Pushed the plug in and the problem was solved. Me bad.

Sounds like you must have bought the Dell without an OS. Have you tried a different OS?

The system ran for about 10 hours last night while running Prime95 without crashing. The failures have always happened while the system was idle and I was away. Which makes me think about the power saving modes. Perhaps Saltgrass' point about the number of USB devices might offer an approch to fault isolation. I can easily disconnect most of them by disconnecting the USB hub to see if it crashes with most of the USB devices disconnected.

To Deeppow's question, I reinstalled Win 7 over Dell's Win 7 install when I got the system. I have not run other O/S other than under VMware and of course Dell's standalone utility.

Thanks for the ideas!


I have a question for those in the know regarding system stress testing. I have been able to run Prime95 and Intelburntest for several hours without crashing. Can I conclude that my rebooting issues are unrelated to motherboard/CPU? I have been able to determine this problem is unrelated to other internal components through the process of elimination. If so, I would like to focus on the O/S and the external USB environment. Any thoughts about such steps are appreciated.




If you can run IntelBurnTest for several hours, your machine is stable. I think you should move on to consideration of other potential issues.


EDIT: This means your motherboard, CPU and memory are OK.

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Postmortem update – Problem resolved:

I wish to thank those that contributed their insight into my system issue and report what I’ve determined what the underlying issue is.
Apparently, the Dell XPS 9000 power supply is sensitive to UPS power backups that do not provide pure sine wave power. I had my system connected to Tripp Lite standby backup that apparently provides marginal power for this computer. I had misled myself into thinking that the issue was NOT power related because I could remove the power from the wall and the system seemed to run fine on standby power, and secondly, the AMI BIOS option to NOT restart after power loss is enabled.
As it turns out, the system disregards that BIOS option and reboots if power is lost for a brief interval, something like one second. Additionally, the Tripp Lite seems to occasionally go into some periodic maintenance mode that results in the Dell PSU sensing momentary loss of power.

One day I happened to hear the click of the Tripp Lite doing its thing and at the same time witnessing the system restart. Further investigation confirmed the faulty behavior of the BIOS option. Of course when I spoke to someone in the business of repairing UPS backups, they confirmed the issue with the XPS PSUs and also said that high-end Macs have the same problem. After removing the system from the Tripp Lite, all is well. An industrial grade APC backup with pure sine way output is in the mail.

So there you go…


Interesting, thanks for letting us know the outcome.

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