A Windows 2000 SBS must have AD and be in a domain setup or it will not run

 I'm having trouble mapping a Windows SBS 2000 shared folder over a
 VPN
 connection. This is a stand alone server in a workgroup (no AD,
 Routing and Remoting, etc - just a plain file server).

 I was having the same issue accessing a Windows XP shared folder in
 the same LAN,
 turned off Windows firewall and it worked.

 Question is, where/how can I allow access to a shared folder in SBS
 2000 from a VPN connection?
 (I can't even ping the server over the VPN)

 Thanks in advance.