I'm trying to backup the database on a dedicated server running SQL Server 2005. The Management Studio installation got messed up somehow and I get an unhandled exception everytime I launch it and ...

Do you have a BackupExec SQL Agent CAL? You can't (well, shouldn't) back up the MDF/LDF files directly. If you have the CAL, BackupExec will use VSS to do a snapshot and backup a consistent copy of ...