Recovering from "SYSTEM Hive Corruption" on Dual-Boot Computers (124566)

SUMMARY

On a dual-boot computer, configured to boot both Windows NT 3.1 and Windows NT 3.5, if you attempt to start the Windows NT 3.5 system after changing the configuration of the Windows NT 3.1 system, Windows NT 3.5 may fail to boot with the following message displayed on a black screen:

OS Loader V3.1
....
Windows NT could not start because the following file is missing or corrupt:
\WINNT\SYSTEM32\CONFIG\SYSTEM

You can attempt to repair this file by starting Windows NT Setup using the original floppy disk or CD-ROM.
Select 'r' at the first screen to start repair.
Boot failed

This message implies that there is a problem with the Windows NT 3.5 SYSTEM Registry hive. This might not be the case. It may be possible to fix this problem without performing an emergency repair on the Windows NT 3.5 Registry. An emergency repair of the Windows NT 3.5 System Files may rectify the problem.

MORE INFORMATION

This message usually appears after modifying the Windows NT 3.1 side of the dual-boot system by doing one of the following:

Performing an Emergency Repair on the Windows NT 3.1 system
Applying a Service Pack to the Windows NT 3.1 system
Installing a new copy of Windows NT 3.1 on the computer.

All of the above actions cause the Windows NT 3.5 versions of C:\NTLDR and C:\NTDETECT.COM to be replaced with older Windows NT 3.1 versions.

The internal format of the registry was changed between Windows NT 3.1 and Windows NT 3.5. This prevents the Windows NT 3.1 NTLDR from booting the Windows NT 3.5 system, because it cannot locate startup information in the Windows NT 3.5 SYSTEM hive.

Performing an Emergency Repair of the Windows NT 3.5 System Files may rectify the problem, as this procedure will reinstall the Windows NT 3.5 versions of NTLDR and NTDETECT.COM. This may be a more convenient recovery option than an Emergency Repair of the Registry, if, in fact, the downgrading of these files is the cause of the boot failure.