Ghost doesn't detect my Backups

I have a problem with norton Ghost at may work. I backuped about 30 PCs and it all works fine. But when I try to restore these PCs they are not listed (5 on the first backupdrive). I must search for them and that's not such a problem for me but for my boss it is. 

I hope someone can help me, so that i don't have backup them all up again.