Do you have File and printer sharing for Microsoft networks listed in your network configuration

He said he had shared drives, so I'm guessing it's in there.

and also Net BEUI?

This is not necessary to be able to see computers in a Workgroup, and in fact, I would highly recommend that NetBEUI be de-installed on all systems unless you have a specific need for it. It's Microsoft's old proprietary networking protocol and nobody uses it any more. I wouldn't be surprised if it was riddled with security holes. It's my long-standing policy to disable any services on any Windows box that aren't actively being used.