Restoring Model Database and Tempdb in SQL Server 2000
You Need To Be Ready To Restore the Model Database - Don't Worry About Tempdb
Description:
The model database should be backed up fairly regularly. Basically, the model template serves as a template for all future databases that are created on the server. To restore the model database, see the Lost Database - Simple model.
The tempdb database doesn't and shouldn't ever be backed up. It is actually recreated every time SQL Server is started.