The 3 setup diskettes that come with SBS do not offer the option to repair your installation.
Create a new set of diskettes by typing:
<Drive:>\i386\winnt32 /ox or <Drive:>\i386\winnt /ox from the CD-ROM.
Rename the Winnt.sif on the second diskette by typing:
ren a:\Winnt.sif a:\Winnt.bak
When you boot these diskettes, you will be offered the Repair option. See tip 272.