• You're trying to restore a backup from a higher version of SQL Server (2008R2 / 10.50.XXXX) to a lower version of SQL Server (2008 / 10.0.XXXX) which can not be done.  The version of SSMS you used to fire off the backup is immaterial, you'd be getting similar problems if you created the backup with SSMS 2008R2 or 2008.