You have no need to uninstall/reinstall SQL Server. You will easily get back your MSDB database from the corrupted instance by the using of a third party utility.
Backup of SQL database MDF file is a crucial aspect in term of company legacy. So the way to recover SQL MDF backup must efficient and robust which very beneficial for data integrity. The use of SQL backup recovery software is a reliable and distortion which gives you expected and desirable results.
Go through this for recovering SQL database backup: – http://www.sqlrepairtool.org/sql-server-backup-restore-software.html