Das geht mit regedit.exe
Wenn du das Programm mal im RealMode (DOS ohne Windows, nicht Dos-Box) ausführst erhälst du folgende Meldung:
C:\WINDOWS>regedit.exe
Imports and exports registry files to and from the registry.
REGEDIT [/L:system] [/R:user] filename1
REGEDIT [/L:system] [/R:user] /C filename2
REGEDIT [/L:system] [/R:user] /E filename3 [regpath1]
REGEDIT [/L:system] [/R:user] /D regpath2
/L:system Specifies the location of the SYSTEM.DAT file.
/R:user Specifies the location of the USER.DAT file.
filename1 Specifies the file(s) to import into the registry.
/C filename2 Specifies the file to create the registry from.
/E filename3 Specifies the file to export the registry to.
regpath1 Specifies the starting registry key to export from.
(Defaults to exporting the entire registry).
/D regpath2 Specifies the registry key to delete.
HTH,
Stefan