Win XP Home machine keeps rebooting on startup

I'm working on a Win Xp Home edition PC for one of my customers and the machine keeps rebooting in a continous cycle on startup. There are several topics on these pages relating to the rebooting cycling but none of them (that I've read) specifically address my symptoms exactly. I've tried to boot in safe mode; used repair feature in recovery console including copying files from the windows repair folder; booting to last known good config, and several other tricks posted on this web site, all without any luck  I finally put another hard drive with a 'clean' version of XP into the machine, made it the primary boot drive and made the 'troubled' drive the slave. With this setup the machine boots up without a single problem. Fans (CPU and power supply) are running fine and nothing appears overly hot inside the box. I replaced the memory just for the heck of it. With the machine up and running on the 'temporary' drive I can see the troubled drive, read, copy, move files, folders, etc at will. I ran check disk and every other utility I could think of. My customer tells me that he did not install any new hardware or software prior to ths error and that it first occured when he was surfing the web using AOL (UGH). I'm thinking that my next step is to copy user data files and settings over to the temporary drive and reinstall XP Home on the original drive. Anyone have any other suggestions before I start a re-install?
Who is Participating?
LeeTutorConnect With a Mentor retiredCommented:
If you've got the problem XP disk hooked up as a slave, you need to use the technique of offline registry editing in order to change the value that controls automatic reboot on error, so that you can see the error message.  Here is the setting that is  involved:

click start | run | regedit

Key: \SYSTEM\CurrentControlSet\Control\CrashControl
Name: AutoReboot
Value: 0 Disable automatic reboot
Value: 1 Enable automatic reboot

Windows Registry Editor Version 5.00


How to do the offline registry editing:

Boot up in a parallel copy of XP.


If the information you want to access was in HKEY_CURRENT_USER: Highlight HKEY_USERS, choose "Load hive" from the File menu, open

C:\Documents and settings\<UserProfileName>\ntuser.dat.

When asked for a name, choose "OldProfile" (or whatever other easily remembered name you choose).  Access/backup the keys you're interested in. Once you're done, highlight the "OldProfile" key, choose "Unload hive" from the file menu.

If the information you want to access was in HKEY_LOCAL_MACHINE\System or in HKEY_LOCAL_MACHINE\Software: Highlight HKEY_LOCAL_MACHINE, choose "Load hive" from the File menu, open




(no extension). When asked for a name, choose "OldSystem" or "OldSoftware" (or whatever). Access/backup the keys you're interested in. Once you're done, highlight the "OldSystem" or "OldSoftware" key, choose "Unload hive" from the file menu.
Have you scanned the drive in question for virus' and malware?
Fiat2000Author Commented:
No I haven't. Is there a particular program/utility you'd recommend?
Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Have you tried this?

Is it the same method you used to copy files from the repair folder? If it's not, it may just be worth a try to follow it exactly as it's laid out.

This process has helped me save 2 different systems with the same symptoms.
AdAware  <-just released their second edition SE, that's the one you want.

If they do not have an anti virus program, there is a good free one available at

And good free firewall can be found at
You can also try these commands in recovery console:
fixboot c:
(fixes boot sector)
(fixes the master boot record)

To get to the recovery console just boot from the XP CD, then select "R" for recovery console and then log on.
Then just simply type the following commands from the command prompt:
fixboot c:
Fiat2000Author Commented:
Yes, I did try that procedure prior to putting in the 'clean' hard drive. When that didn't work I also tried the same procedure using the Windows GUI from the 'good' O/S since the system files on the problem drive weren't in use and I could copy/delete as needed.
Fiat2000Author Commented:
Nelsonjr71...  Tried all of the commands in recovery console that you mentioned.   That's the main reason I put 500 points on this one. It has me totally stumped. I just finished running AdAware and found 91 files. I'm now running Spybot. Don't know whay I didn't try them before this. Just tied I guess.
Hmm... Exactly how far does the system get in the boot process before rebooting? Do you get to the point of logging in? Is there any sort of error messages that occur before the reboot?
Fiat2000Author Commented:
nelsonjr71. I got so tied last night I crashed, my appologies for not getting back sooner.  In response to your last quesiton about how far I get in the boot process, I never get to login it at all. I get the xp little sliding bar that indicates that its loading then the screen goes blank for a second or two and then it starts reloading again. You mentioned an error message and I watched the screen closely. Lo and behold there is an error message!. It comes up and goes away so fast that I don't have time to see what it says. Probably help lots if I could see it? Any ideas on how to pause the screen long enough to read the message? With respect to woodendude's comments I downloaded AdAware-se and ran it,  found LOTS of erros and fixed them...problem stil exists.  
Fiat2000Author Commented:
Lee, followed your steps and got through the procedure without problems. Now what happens is that the bootup is no longer in a loopback mode. It stops at the error message which once flashed by so quick that I couldn;t read it. The error message is "Stop c000021a {fatal system error} The session manager initialization process terminated unexpectedly with a status of 0x000026c the system has been shut down". I've researched this error and tried several of the steps that others suggest under different discussion strings and haven't cured the problem. Most of the discussion strings for that particular error message suggest that the problem lies with a hardware device or memory. However,  this system runs fine with the temporary hard drive. Any suggestions on wheree I should go from here?
Have you seen this page on troubleshooting STOP errors?

Here is some general advice for troubleshooting STOP errors from that page:

General Troubleshooting of STOP Messages
If you can’t find a specific reference to your problem, running through the following checklist stands a good chance of resolving the problem for you. This checklist is also usually the best approach to troubleshooting some specific Stop messages, such as 0x0A and 0x50.

Examine the “System” and “Application” logs in Event Viewer for other recent errors that might give further clues. To do this, launch EventVwr.msc from a Run box; or open “Administrative Tools” in the Control Panel then launch Event Viewer.
If you’ve recently added new hardware, remove it and retest.
Run hardware diagnostics supplied by the manufacturer.
Make sure device drivers and system BIOS are up-to-date.
However, if you’ve installed new drivers just before the problem appeared, try rolling them back to the older ones.
Open the box and make sure all hardware is correctly installed, well seated, and solidly connected.
Confirm that all of your hardware is on the Hardware Compatibility List. If some of it isn’t, then pay particular attention to the non-HCL hardware in your troubleshooting.
Check for viruses.
Investigate recently added software.
Examine (and try disabling) BIOS memory options such as caching or shadowing.
NOTE: When a STOP message occurs, Windows can create a debug file for very detailed analysis. To do this, it needs a workspace equal to the amount of physical RAM you have installed. If you resize your Win XP pagefile minimum to less than the size of your physical RAM, you will get an advisory message that your system may not be able to create a debugging information file if a STOP error occurs. My advice is to go ahead with this change if you want, but simply remember the limitation so that you can change it back if you need to troubleshoot STOP messages. Some general troubleshooting principles are suggested in the Resource Kit for approaching STOP messages overall.

Troubleshooting Stop messages: General Strategies
Troubleshooting Specific Stop Messages
MSDN List of Win XP STOP Messages (If not a complete list, this one certainly is extensive!)
Blue Screen Preparation Before Contacting Microsoft {KB 129845} Win NT, Win 2000, Win XP (General remarks on STOP messages)

You will need to go to the actual page to be able to click on some of the links to Microsoft articles.
Fiat2000Author Commented:
Thanks Lee, I'll give it a try
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.