Windows 2000 server

I had 4 NT servers and 29 client (Win2000 prof. and Win98 clients) and 6 NAS file servers. I have 26 users. I migrated 2 NT Domain servers over to Windows 2000 server. Everything works fine, one of my Win 2000 is running DHCP, DNS and WINS. When I purchased the Windows 2000 upgrade I paid for 30 Open Bus. Windows CAL 2000 Engish OLP NL. All users usallay work days only and are logged in on their own computer most of the day. I keep getting 202 License Service event errors on one of the Win 2000servers. When I check this server my Lic mode is set at Per Seat and shows 38 reached. Question Do I need more lic ? and how do you add more lic. to a per seat setup ?