Seems like you are trying to Restore database backup taken from SQL Server 2008 R2 into SQL Server 2008 machine and hence obtaining the error..
Since you can't restore database backups from later versions into older versions of instances, use Database Publishing Wizard to create the script of your entire database and run this script in the server which you are trying to restore.
http://www.microsoft.com/downloads/details.aspx?familyid=56e5b1c5-bf17-42e0-a410-371a838e570a&displaylang=en