Possible reasons for the subject disaster are:
1.A fatal system error (STOP error) causes the computer to stop and the Automatically Reboot option is enabled in Control Panel / Startup/Shutdown.
2. Pagefile.sys is smaller than the amount of physical memory installed in the computer or there is not enough free space to write the Memory.dmp.
To help resolve these problems, install another copy of Windows NT on a Different Drive or Partition or Folder. Run Regedt32 and select HKEY_LOCAL_MACHINE. Load the original System hive (see tip 182) and set AutoReboot to 0 in each ControlSet at:
Collapse the HKEY_LOCAL_MACHINE subkey and unload the hive. With AutoReboot disabled, you may be able to research the stop message.
If the problem is an improperly sized pagefile, load the System hive as above and edit:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSetxxx\Control\Session Manager\Memory Management
Set the pagefile to at least RAM + 12meg by double clicking PagingFiles which should be a REG_MULTI_SZ type and formated like:
<drive>:\pagefile.sys nnn nnn
where each drive is a separate line and nnn nnn is the minimum and maximum pagefile size. Do not set it greater than the available free space. Edit:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSetxxx\Control\CrashControl and set CrashDumpEnabled to 1.
Collapse the HKEY_LOCAL_MACHINE subkey and unload the hive.
Restart your original installation. A dump should be written to the pagefile. Boot the new alternate install and use dumpchk.exe -v or dumpexam.exe (CD-ROM debug folder or updated from a service pack) to read the NewNTFolder\Memory.dmp to help resolve the problem.