How to recover from a corrupted registry that prevents Windows XP from starting:
http://support.microsoft.com/default.aspx?scid=kb;en-us;307545MORE INFORMATION
When you try to start or restart your Windows XP-based computer, you may receive one of the following error messages:
Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM
Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SOFTWARE
Stop: c0000218 {Registry File Failure} The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE or its log or alternate
System error: Lsass.exe
