There are two ways to drop a dump device using SQL Enterprise Manager: from the Database Backup/Restore dialog box while you manage backup and restoration, or directly from the Server Manager window.
When you drop a dump device, all data that has been backed up to that device is also dropped.
A confirmation box appears.
The dump device is dropped.
You must delete the device's filename from the directory where it is located. Use File Manager or the operating-system del command. It is not necessary to shut down and restart SQL Server.
The Database Backup/Restore dialog box appears.
The Edit Dump Device dialog box appears.
A confirmation box appears.
You can also drop a dump device by using the sp_dropdevice stored procedure. For information, see the Microsoft SQL Server Transact-SQL Reference.
Dropping a device removes the device from the sysdevices table.