About Internet Rights

Hi,
I have one w2k advanced server with active directory installed on it.I have 15 Windows 98 systems and 20 Windows 2000 professional computers.All are connected to domain.I also have 128 kpbs isdn connection.I am using the Class C IP address.I want my windows 2000 users can use internet not windows 98.How i restrict my windows 98 users.

With regards.

Anurag.