If you receive the following message when you attempt to start Windows NT:
Windows NT could not start because the following file is missing or corrupt:
\%winnt%\SYSTEM32\CONFIG\SYSTEMHardware Profile/Last Known Good menu
the System subkey of the HKEY_LOCAL_MACHINE registry hive is too large.
Microsoft says that the only resolution is to use an Emergency Repair Disk or perform a reinstallation of Windows NT.
There is another option you can try first:
1. Boot to an alternate install of Windows NT.