I have 12 computers with one acting as the database.
Therein lies your problem. With 12 computers, you will have 11 computers in your network attaching to the "server."
This has nothing to do with the database. It has to do with your peer-to-peer. In my estimation you have three options:
1. Take one computer off the network. If you have a computer which does not need to access the "database computer," you can disconnect it -- not from AC but from the network. Keep in mind that other network peripherals can count.
2. Go with an NAS that will allow more than 11 connections.
3. Purchase a server which can run a server OS. That would, as you say, mean purchasing a server, server OS and CALs.
Be sure that the "server PC" is either Vista or XP Pro.
