What should I back up?
Applies To: Windows SBS 2008
You should back up the system drive (typically, drive C). You should also back up any drives that store business information such as:
Exchange Server data
Windows SharePoint Services data
SQL Server databases that support your line-of-business applications
Redirected user's My Documents folders
User's shared data folders
You can only back up data from a local drive that is formatted as an NTFS file system. Drives formatted as FAT (including FAT32) file systems do not appear in the list of drives to back up.