Adding more workstations to network

I’m a computer tech at a small retail outlet.
I recently rebuilt the network with new workstations and a new Point-of-Sale program.
The “server” is a P4 1.8, 512 DDR RAM, and 60GB HD, running w2000 Professional.
The stations are Windows 98 machines.
Problem:
I can only connect 10 systems to the server. The rest can see other workstations but not the server. How do I get past the maximum allowed users of 10 under the share properties of the server HD?

Any ideas would help.
Thanks