I wrote tip 2914 » A Windows 2000 Service Pack does NOT have to be reinstalled when you change Sytem State?

There are circumstances after you have performed an emergency repair operation that do require the reinstallation of a Windows 2000 service pack.

When you install a Windows 2000 service pack, the %Systemroot%\Repair folder is not updated, by design.

If you installed Windows 2000 from a slipstream of the latest service pack,

                                   OR

ServicePackSourcePath points to the latest Service Pack and HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath point to a slipstream of that service pack

you DO NOT have to reinstall the service pack after a repair. In all other cases, if the repair replaced system files, you must reinstall the latest service pack.

NOTE: When you install a servie pack, you MUST update the %Systemroot%\Repair\Regback folder by using the Emergency Repair Disk feature of NTBackup and checking the Also backup the registry to the repair directory box.