JSI Tip 0860. SP4 - SBS has been detected, but your computer is not an SBS server.

When you reboot after an SP4 install, you may receive the subject message, even though your computer is not an SBS server.

Update.exe from SP4 checks for the existence of

HKEY_LOCAL_MACHINE\Software\SmallBusiness.

This key can exist if your computer is a member of an SBS domain.

Click OK to dismiss th message, it will not re-occur on subsequent reboots.