My computer is automatic reboot looping [Solved/Closed]

 venkat -
my computer is stuck in a reboot loop. I have an intel pentium 4 desktop computer. it is windows xp home edition. the problem happened after I installed the windows service package 2 (i know, im a little behind). it seemed to install the update fine but after I restarted my computer I couldnt seem to get to my desktop. the computer manages to get to the light blue windows xp loading screen but instead of entering my desktop the computer reboots and the whole process starts over again. after reading other forums, I tried the F8 method but couldnt seem to make it work. last known configuration and safe mode dont seem to work but I may have not done them correctly; im no computer whiz. but after pressing the "disable automatic restart on system failure" option, I got this error message on the "blue screen of death" (this happened after the light blue xp loading screen instead of it restarting like it usually does):
STOP: c000021a Unknown Hard Error
Unknown Hard Error

what should I do? I dont want to have to reinstall windows xp and lose my data as I have some important documents and music mp3s on it. ive read about possibly doing a repair install? how does that work, would it work, and would it save my data? is there another option? thanks in advance.

Configuration: Windows XP

18 replies

hi guys
try this..just repair your operating system...i did not try this because its too late for me to know thats why I want to tell you guys how to solve your problems.and I hope that it will work for you all..

* Set your first boot device in the Bios to CD-Rom. Insert your Windows XP CD, save the bios settings and exit. Soon "Press any key to boot of CD" will appear on the screen, hit the space bar to continue.
* Now setup will inspect your hardware and software, it then will load various files required for the repair. Just wait and be patient, this may take a few moments.
* Soon a menu will appear (as pictured below), press enter to continue.
* Now the "End User Agreement" Press "F8" if you agree, "ESC" if you don't.
* You will now have to select the installation you wish to repair. Usually there is only one, but sometimes, there may be 2 or more (i.e. you have done a parallel install to resolve a problem), use the up/down arrow key to select the install, and then press "R" to continue.
* Setup will now examine the disk be patient, it can take a few minutes.
* Setup will go through a percentage - 1 to 100%
* A screen will soon appear. Press "F3" to continue
* Now setup will reboot system, wait 15 seconds or just press enter.
* Now it is time to see if this has solved your problems.

hope it work.....goodluck
Thank you

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This information was extremely helpful! Thank you!
Thank you sir it helped me, thank you once again.
its very helpful
its very usefull thanks-nisar ahmed uae
very helpful yar
The problem you are facing may be the result of 1 in a million possibilities, or a combination of a few [can I be any more general than that?]. The good news is that you can use a systematic approach to resolving the issue, but it will take some time.

Some plausible reasons why your -- or anyone else's computer system, for that matter -- isn't working properly may be related (but not limited to) any one or more of the following:

a corrupt file on the hard drive
a corrupt Windows system file
a corrupt or incompatible hardware driver
a newly installed program
a Spyware or virus infection
a hardware error [bad ram, video card, etc]
Possible Solutions

First, make sure that you don't have Windows XP to automatically reboot during a System Failure. This will allow you to view an error message from within Windows that is associated with your problem. Once you have the error message, write it down and then search for the error message using Google (even if it's a bunch of numbers).

If you don't receive an error message and your computer is still continuously rebooting, I would tend to think it may be a hardware issue -- perhaps one the cards inside your machine isn't plugged in all the way? Try unplugging and re-plugging each card into its respective slot. Make sure the slot and card interface are free of any dust, and then proceed to seat the card into the slot again (ensure there is nothing obstructing the card and never force it to go in).

As for resolving the problems I mentioned above:

For a corrupt or inconsistently reported file on the hard drive: run CHKDSK [check disk] on the drive. Go to My Computer, right-click the C drive, select Properties, and then go to the Tools tab, and select Check Now. Choose 'automatically fix file system errors' and Start. Repeat this process for all hard drive letters in your computer.

For a corrupt Windows system file: There really isn't any way to know if this is the case, unless Windows is reporting a problem with a certain system file. In most cases, CHKDSK [discussed above] should resolve any problems related to your file system that can result in a corrupted file; but if that doesn't fix it, you can try issuing a System Repair. Note, however, that I would not recommend issuing a repair or restore unless you have exhausted all possibilities because you will have to reinstall all Service Packs and hot-fixes once your system has been reverted. As for opting to do a System Restore versus System Repair: a restore will only revert your System Registry (which very well may solve your problem) but does not [as far as I know] restore corrupt system files.
thanks for this information...I had the same problem and when I run chdsk the problem solved... and the pc run normally
Hold off the reformat, reinstall operation...

I had the same problem, and since my old computer had started acting up for awhile, instead of going for the reinstall option, I decided to buy a brand new machine: Quad, etc...
I connect my old monitor, old mouse/keyboard combo, and bam! same looping problem...

So it has to be one of the external device... Someone mentioned monitor cable?
I'll borrow one from work tomorrow and report back...
worked for me. thanks
As the comp restarts, press F8 to go and select safe mode. Press enter
Look at the bottom of the screen for "Press Esc to ...sptd.sys. Pres esc immediately
When a dialog box about safe mode show click OK
Close system restore screen if it shows up
You should be able to see your Desk top in safe mode.
Go to"C:\WINDOWS\systems32\drivers\sptd.sys"
Rename sptd file to something you won't forget in case you need to go back to it
Close the window.
Reboot you comp
you will not lose you data,just repait the operating system using the windows XP Cd. go for an option of repairing no installing a fresh copy. or you can remove your hard disk and instal it on another computer as a slave so that you can retrieve your data and then format thedisk after retrieving your data thru creation of a backup, dont worry you wont lose ur data..........carol
how do you get the system to reload the operating system from the disk? I put in the disk, but the reboot process keeps on going and the disk never gets to run
Hi, I just saw your error message and thought I could offer a suggestion. If your operating system came pre-installed on your computer, the reason it may not be loading from the disk is that the boot sequence is telling it to load from the hard drive and it can't get past that. Try putting the disk in the CD-ROM, restarting the computer and hitting F12 (that is the usual command to get to the boot sequence). Once you get there just arrow down to DVD or CDROM and hit return. It should tell the computer to pick the CD ROM first.

I hope this helps.
I have had three laptops do this within our organization (just all of a sudden - they will start a continual reboot). When the Windows XP SP3 CD is put in and I try to run a repair, it won't find a hard drive. The fix for this is to boot into the BIOS and change the mode from SATA to COMPATIBILITY mode. I changed this on all three and now they are working fine. This might have occurred after a Windows update. Not sure as I had all three users complaining at different times.
computer is stuck in a reboot loop. I have an intel pentium 4 desktop computer. it is windows xp home edition. the problem happened after I installed the windows service package 2 (i know, im a little behind). it seemed to install the update fine...
ms. you are not install window xp properly thats why your system is re booting again and again
one think : that you will open your pc cover and then you will reconnect the hardware connections ok

this is the answer for "Timothy Sauls "
hello here
make secondary hard drive to and install xp and the copy all files from master or error ed hard drive this make less time and get problem solved I will go this and get my system back to work with in 2 hours
after transferring data remove secondary hard drive which have backup data

and now format complete partition and reinstall windows xp and get back to work
When XP keeps on rebooting, the most likely problem is, that your boot config has gone haywire. To fix this try to boot from the XP home cd , do a repair on the current selected installation. in dos mode run bootcfg /rebuild. That should fix your problem if not try to repair windows by reinstalling all dll, this will not destroy any data
above solution is good that solved my problem
I had the same problem and now I have it again. This is a virus I have nbot isolated neither identified. But it is always in the machine if somebody plays the games on the web.
To repair it you have to get live CD of Linux (e.g. Fedora distribution). Boot from that CD and better ask a linux specialist to backup your data from the partition(s) on the infected HDD (usually SATA drive) to external drive (USB or another SATAor PATA). Then remove partition(s) from infected discs.
Create new NTFS partitions on the HDD still under Linux. Reboot to Windows. Format partitions created under Linux. Restore data from external drive. And never play the games on the web. There is no effective firewall neither antivirus that can help you out of this problem. So far the only above described steps will help you. Dont believe Windows saying (even on tech help) that your (SATA) drive is damaged. It has just a virus in a partition that causes reboot Windows immediatelly after the infected partition is touched. That is why your Windows never boots up completelly.
Write me back if you have succeeded.
nope... I didnt manage to solve the problem. I transfered it back to my old processor and it works fine. like before... still dont know whats the reason.

definitely not virus coz when I reconnect it to my old processor, windows booted up fine. no hassle.

The problem is what microsoft did when building Windows XP.
As a security measure, microsoft designed Win XP to check computer hardware at boot-up. If your hardware profile is not the same as when it was installed you get the blue screen of death. I found this out when my ex-wife fried my mother board and I had to replace it. I re-formated, but when I replaced my sister's MB somehow I found a program and copied everything to a slave and then overwrote everything on the fresh install. It gave her everything she had, just was teidious...
Registration date
Friday December 26, 2008
Last seen
December 29, 2008

probably virus! you can repair windows with installation CD
or you can use some distribution of linux (LIVE) and download your data on USB... and after reinstall Windows
the easy thing to do is restart you computer in safe mode and do a system restore before you had put sp2 on you computer.

i had to do this and I install my xp with sp2 on the disk as I created the disk my self

try system restore
you should turn off ur pc
then remove the RAM and processor and remve dust frm them and clean the slots of RAM and then processor connecting place....
again connect all parts at appropiate location...
turn on ur pc... thn ur pc will work..
if its still creating problem??
Change ur RAM
i have HP laptop. Two weeks ago, I bought HDMI Cable to enable to watch movie installed in my laptop by using HDMI Cable to my LCD 32" TV. To my surprise, my laptop automatically rebooting or restart.

Please advise.
Not enough information to say for sure.


It rebooting after Bios, but before Windows Loading Screen. (commonly a hardware, graphics card, Boot issue)


Is it during or after the Windows Loading Screen?(commonly a boot issue, registry issue)


Is it after you attempt to login to windows? (commonly a registry issue)


Is it as you initiate a start a particular program? (commonly a software driver issue)


is it while you are using that particular program? (commonly a software driver issue)


is it at Random after you've logged in for more than 1 minute? (Which is commonly caused by overheating.)
plz update your bios.
Hello Everyone,

If you have another hard disk make it primary and boot you computer from that hard disk. After windows open run chkdsk from command prompt.

All programs -> Run -> cmd -> chkdsk /f. It will check booting sectors for any errors.

Thanks and Regards
I had a similar problem where the monitor would say entering power save mode and then restart. The problem started after I had a faulty graphics card replaced. I have a dell computer and when the problem started they promptly replaced my mother board and graphics card and the tech reinstalled Vista. However after a couple of days the problem reappeared. On speaking to them again the tech asked me to change the cable to VGA from the DMI port as that could be the reason for the problem. I did that and watched 4 episodes of 24 the serial without any problems.

The reason he explained was the the HDMI cable could be causing the GC to overheat resulting in the computer restarting.

Seems to have worked for me you could try it out too if you are using a computer which is connected to your monitor through a HDMI cable.

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