Believe me, I know it's not a good idea. The version of Backup Exec that we have won't work with Advanced Server, only Server and Professional. The Advanced Server version costs more. I only asked because my boss wanted to know, because there are a TON of shares on the machine, and recreating them would be a pain.
Since I posted this, he decided to go ahead and pay for the upgraded version of Backup Exec, so the whole point is moot, anyway. ;(
Thanks anyway!