If you can boot to another XP installation on the computer then you can
use Regedit on the working installation and load the System Hive of the
broken installation and change the CrashControl AutoReboot registry value.
1. Run Regedit.exe from the running XP installation, and then go to the
HKEY_LOCAL_MACHINE key and highlight it.
2. On the Registry menu, click Load Hive, and then open the System hive
in the broken Windows XP installation location. By default this
installation is located at %SystemRoot%\System32\Config\System. The
file is "System" without an extension.
3. Enter an arbitrary name when you receive a prompt for a key name in
the Load Hive window. This loads the original HKEY_LOCAL_MACHINE hive as
a subkey of the current key.
4. Change the value data in the AutoReboot value to 0 (zero), instead of
1, in the following key:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CrashControl
*** See ControlSetNNN note below ***
5. Collapse the HKEY_LOCAL_MACHINE subkey and unload the hive.
This disables the Automatically Reboot option in the original Windows
installation. After you follow these steps, you may be able to gather
information from the STOP error message and resolve the problem that
prevents the computer from starting.
Look here for easy to follow example:
http://www.rwin.ch/xp-live/regedit.htm
*** You will notice that on a dormant XP system the registry has no
CurrentControlSet key, it only has ControlSetnnn keys (ControlSet001,
ControlSet002...) The CurrentControlSet key is created from one of the
numbered keys when the computer reboots. To determine which Control Set
will load when computer boots look at the
HKEY_LOCAL_MACHINE\SYSTEM\Select key. The numbers there indicate which
Control Set will be loaded depending on which boot option is chosen.
Edit the AutoReboot value in the appropriate Control Set.
John