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How can a running system suddenly reboot and show the message:
Disk Boot Failure - Insert System Disk and Press Enter instead of booting the OS?
It doesn't seem to be caused by a defective physical disk. Can the disk controller cause it? How can I prevent this happening again?


  1. This time, the computer was running Win7 and was always on. Automatic updates are disabled; the computer should never reboot by itself unless there's a power outage, which there wasn't. (Brownouts don't occur where I live.) There are no USB devices attached.
  2. I came home and found that the machine had apparently rebooted and was showing the message:
    Disk Boot Failure - Insert System Disk and Press Enter instead of booting the OS.
  3. I had this exact situation once before -- on the same machine but running WinVista -- and a simple chkdsk solved the problem. But on Win7 that trick does not work. I can't access the event log because it doesn't boot. The Samsung 1TB hard-disk itself is only a few months old. I have not tried Tune HD.
  4. I tried booting from the Win7 installation DVD and repair the installation, but the DVD kept hanging during boot. Something was preventing setup from starting, and booting the DVD in safe mode showed that it hung during or after loading the disk driver.
  5. The same disk wouldn't boot in another computer either, same message.
  6. I installed Win7 on a new physical disk -- that worked. After letting the machine run for a few hours (nothing installed, just a totally clean Win7 without any updates), I came back to the machine and it again showed that message! On a new disk!
  7. I'm beginning to suspect that it's not related to the physical disk, and not to any installed software either. I don't like to install again and then sit for hours and watch the screen, just to try to discover why/how/when this happens. I'm now not sure what to do, what to fix.

I don't want to install Win7 over and over again, and I need this computer up and running as soon as possible. I don't want to have to replace components one by one either until it's a new machine next to a drawer full of junk...

Can this error be caused by a malfunction in the disk controller, or perhaps in the power supply? I don't have any spare components lying around that I could test.

One month has passed and the machine has worked fine. Now, it just happened again, the system disk won't boot. Luckily I've now learned to keep important stuff on secondary drives, so I'm just going to format and re-image the system disk and see if it helps. And I'll install a new disk controller at the same time, to make sure the onboard controller won't crash the new image as well. This is getting tiresome.

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Be sure you don't have any usb devices connected besides keyboard and mouse. Replace the hard drive data cable. – Moab Jul 25 '10 at 23:32
I did say that I don't have any USB devices attached. I didn't state that I also tried a different cable (from above "step 6" and onwards) to no avail. – Torben Gundtofte-Bruun Jul 26 '10 at 11:20
I wonder if the cmos battery is failing or is corrupting the bios, I have ran across this on a bunch of Dell PCs in the past, replacing the battery corrected the issues I was seeing, might be worth a try to replace the cmos battery and check the battery socket for corrosion when you do. Another thing it could be is a faulty PSU, not spinning the hard drive up in time to communicate with the bios. – Moab Jul 30 '10 at 17:34
Moab, the machine is fairly new, less than 2 years. So a dead CMOS backup battery (and corrosion) seems unlikely, but I will check to be sure. As for a faulty PSU, it would make sense for a cold boot, but if the machine is already running and all devices have power, I think this can be ruled out. – Torben Gundtofte-Bruun Jul 30 '10 at 20:26
up vote 0 down vote accepted

it can be a fault on the connector the hard drive is plugged into. Which is a motherboard fault..

you could try plugging the hard drive into another connector.

Windows version has nothing to do with this.

you could try a new hard drive.

(I had a situation like that with a computer, new hard drive helped for a bit but then same problem - +that solution didn't last long. proving not the hard drive. I then tried moving the hard drive to another connector, then was fine for maybe even a year, but then same thing happened with that other connector. Was ultimately a motherboard fault of course.. and it just delayed the problem.. ultimate solution was new motherboard) Another temporary fix with that thing was booting to recovery consule and doing those 3.. FIXMBR, FIXBOOT, BOOTCFG /rebuild. Was probably FIXMBR that did the temp fix. though didn't go to what caused the corruption.

There are viruses that can write to the boot record, so in theory it could be that., and resetting the MBR could help..

obviously with any movement of the hard drive to another connector(and that may indeed fix it for a good time or "permanently"), you obviously may have to change a setting in the BIOS to get it to boot from that one. (i'm not sayin you haven't.. just saying if you will move the hard drive to another connector as a solution, then, bear that in mind)

added-Try changing to another controller/ mbrd hdd connector..and then doing a repair installation. (to fix any corruption of the windows installation) also, maybe it may help to do fixmbr fixboot .. from recovery console prior to repair installation. You can try skipping the repair installation if you want to save time. The method is this

  • Changing to another controller is the most important thing.
  • Making sure the windows installation that is no longer corrupt and won't start, (incase eg damaced by the bad controller), and making sure the boot record is fine and the partition active. If you want quick methods, then those mentioned.. (just repair installation if you did it, is a bit slow and may require some reinstalls.. chkdsk can be a bit slow(but obviously use the right switch so it fixes errors).. fixmbr, fixboor,.. are quick). note- chkdsk is only one thing and as you say didn't manage it.. but it is always something to try , and as you say, it worked once. It can fix some corruption sometimes. important that you use the fix switch or better, in windows itself, that's /R. In the recovery console the options may be less, and there's a /P. but do /? so you see what options there are. and chkdsk is only one thing..
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What I simply don't understand is how this can happen to a running machine that is not being touched in any way, and that has just been installed on a new disk, on a new cable, on a new controller port (but same on-board controller). How can any sort of repair or fixmbr attempts really solve this? I will have a go at your suggestions for sure. – Torben Gundtofte-Bruun Jul 26 '10 at 11:24
well, if you ruled out the hard drive (since you said this happened with different hard drives), and you installed windows fresh while it was on another controller, and it ran for a bit then went wrong. Then could be -both- controllers are bad. Then your motherboard is just messed up. The solution besides changing of motherboard, was changing the connector your hard drive is plugged into. The only thing fixing corruption is useful for, is if say controller 1 is bad but controller 2 is good, and you're on controller 1, it messes up and you get corruption. – barlop Jul 27 '10 at 2:08
Then you can move the hard drive to controller 2, fix the corruption with fixmbr, chkdsk.. and it'll start running. You yourself found that. You just said it failed -again-. Then a motherboard problem affecting both connectors. But if it only affected one of the connectors, then the fixmbr and moving it to another connector would've fixed it permanently. If you find no problems with the hard disks running windows on a different motherboard(another computer).. Then that's just more reason to think it's a faulty motherboard If you have another controller to choose from then great. – barlop Jul 27 '10 at 2:09
i.e. fixmbr or chkdsk, isn't a complete fix, but it is something that may get windows running, so you can try, say, moving it to another connector.. or better as you suggest, another connector with a different controller behind it - if you have one. And see if it works, without having to reinstall windows.... – barlop Jul 27 '10 at 2:14
On second thought. You may be able to diagnose without fixmbr and without installing windows.. If you put the hard drive in another computer and you get beyond that error e.g. it tries to start windows and crashes. Then in your problem computer you get that error with both connectors. Then you -know- it's your motherboard and that the connectors or what's behind them, is completely dead. – barlop Jul 27 '10 at 2:15

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