you wont be able to recover and entire system to different hardware. Backup Exec is not a migratio product. So if you restoreing user data your fine, but entire system no..when you reboot you will most likely get BSOD.
You errror about the media try the following:
Goto Tools - options - catalogs - and uncheck the box to use storage based catalogs
Stop the backup exec services and rename program files\veritas\backup exec\nt\catalogs folder
Catalog the tape again and then try the restore
