Backup

The database should be backed up regulary. It must be done from the computer which acts as a server (i.e. where you installed full version of Linnworks including database). To back up the database open Start > Programs > Linn Systems > LinnWorks R3 > Tools > Backup

 Select the directory for the backup file. And click Backup. The program will produce linnworks_backup_01012008.bak file, where the ending is the date of the backup.

Restore

To restore the database you will need to install Microsoft SQL Server 2005 Management Studio and connect to the database through the management studio.

Read Microsoft article on how to restore database correctly

http://msdn.microsoft.com/en-us/library/ms177429.aspx