PC reboots on OS load

Hi all,

I have a bit of an issue with my current PC build. It reboots whenever an OS tries to load. It doesn't matter which windows boot option I select, the moment I hit enter the system reboots. I've tried a number of HDDs (which work perfectly on other systems), and the problem still occurs. The problem persists even if I remove all HDDs and attempt to boot a Linux Live CD (everything is loaded into memory, and does not require a HDD).

I'm reluctant to blame the PSU, as I've disconnected all additional devices while trying to find the cause of the problem. I've also been able to run memtest for a number of hours without an issue.

For the above reasons, I suspect that the problem may be centered around either the CPU, memory, or motherboard. While memtest found no errors with the memory, I still can't rule it out due to the Live CD requiring memory to boot.

Processor: Intel Core 2 Quad 2.80Ghz (Q9550).
Memory: 4gb (Corsair TwinX XMS2 6400 -- DDR 2).
HDD: 500gb SATA 2.
Media drives: Floppy disk drive, Zip Drive, Pioneer region free DVD player, Pioneer DVD-RW.
Video: Nvidia GeForce 9800 GTX+ (512mb, PCI-E).
Network: 10/100 Ethernet.
Sound: Sound Blaster Live Audigy.
Motherboard: Asus P5N-D

The system was built in November of last year, and had worked flawlessly until the problem presented. Can anyone help narrow this problem down further?
11 answers Last reply
More about reboots load
  1. Should be able to chek in BIOS if CPU gets hot after a few minutes. Other than that you could test with 1 stick of RAM just to see.
  2. Tried both RAM sticks individually, same problem.

    CPU runs between 55 - 70, depending on load.
  3. Well looks like you have done a good job at finding a diagnosis ;)
    i have been reading up and turns out that this card has a tendency to do that, so i recommend you RMA the motherboard, if you want to see some reviews: CLick hope i helped.

    oh and i also think you should improve cooling on your processor anything close to 80C is bad news.
  4. Assuming windoze XP of some kind??,AND a psu of 550/600w then...
    And that all the hardware is a-ok consider the following...
    If you have it, run Scandisk from a dos boot disk reboot system if no go,,,,,,,,
    then format and reinstall,as it sounds like a corrupted install..:)
    PS. You might try reinstalling right over but if from dos you will lose everything,that is altho stuff will be there it will mostly need to be reinstalled as it will for the most part not be in the registry,some programs need that,some don't..:)
  5. I had a similar problem with several Asus P5N-D motherboards. What used to happen to me was The machines would actully BSOD so fast at windows loading screens that i couldnt see it. Turned out the the drivers that came on the original driver disk were bugged out. I downloaded the newest drivers off asus's slow website and also did a Bios update just in case afterwords. This fixed the problems.

    Odd thing tho is we have Linux as a factor on this one here. Im not sure how Linux is for drivers or how it exactly uses that board. I would see if the machine boots into safe mode into whatever OS your running. Uninstall the drivers and try to reinstall them with newer versions.

    Either way I just can remember having issues with those boards almost everytime i did a build with them.

    Could very well be a hardware problem when thinking about the live CD situation. T

    This could be a tricky one.


    Dokk has a good suggestion also
  6. mallball said:
    Well looks like you have done a good job at finding a diagnosis ;)
    i have been reading up and turns out that this card has a tendency to do that, so i recommend you RMA the motherboard, if you want to see some reviews: CLick hope i helped.

    oh and i also think you should improve cooling on your processor anything close to 80C is bad news.


    I think those temps are due to resetting the bios, and relying on the auto settings. Apparently (from what I've read), if you leave it on auto, temps go through the roof :/ Though I still get the issue even if I've left the system off over night, so it's not a heat issue off the bat.

    dokk2 said:
    Assuming windoze XP of some kind??,AND a psu of 550/600w then...
    And that all the hardware is a-ok consider the following...
    If you have it, run Scandisk from a dos boot disk reboot system if no go,,,,,,,,
    then format and reinstall,as it sounds like a corrupted install..:)
    PS. You might try reinstalling right over but if from dos you will lose everything,that is altho stuff will be there it will mostly need to be reinstalled as it will for the most part not be in the registry,some programs need that,some don't..:)


    Can't do a format or reinstall anything, if I can't boot a single OS in the first place. It's not OS related, as I still get the issue on a blank spare HDD (booting to the windows cd for install), or even without one attached to the system (as I've already mentioned).

    Thanks though ;)

    Anonymous said:
    I had a similar problem with several Asus P5N-D motherboards. What used to happen to me was The machines would actully BSOD so fast at windows loading screens that i couldnt see it. Turned out the the drivers that came on the original driver disk were bugged out. I downloaded the newest drivers off asus's slow website and also did a Bios update just in case afterwords. This fixed the problems.

    Odd thing tho is we have Linux as a factor on this one here. Im not sure how Linux is for drivers or how it exactly uses that board. I would see if the machine boots into safe mode into whatever OS your running. Uninstall the drivers and try to reinstall them with newer versions.

    Either way I just can remember having issues with those boards almost everytime i did a build with them.

    Could very well be a hardware problem when thinking about the live CD situation. T

    This could be a tricky one.


    I've had Linux running off the CD in the past on that system, and it ran fine. As stated, I've attempted various options while booting the machine, including safe mode.

    I'm tempted to think it's definitely motherboard related, and I've read up on a whole host of issues other people have had (though nothing quite like my problem).

    I'll be taking all 3 parts back to the store tomorrow, so hopefully I'll have a definite answer by the end of the day.

    Thanks to everyone for their replies :)
  7. nice to hear will be eager to find out the results. Best of luck on your PC http://img.tomshardware.com/forum/uk/icones/wink.gif
  8. I took the 3 main suspects back to the shop today.

    Motherboard was actually ok, but apparently the CPU and memory were giving them errors. I've had those components replaced, and thankfully my system is back up and running with no apparent loss of data.

    Thanks to everyone involved in helping me with this problem, I really appreciate it :)
  9. Wow bum CPU, quite rare. Usually CPU's are like the list thing to take a dump
  10. all this time I thought it was the power supply. Had that when I did tech support. A short caused reboot, but I guess not necessarily upon os load.
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