w2k server and win 98 se network + cable

there is a w2k server and 10 (or a few more) win 98s im putting in the internet (cable) the chain is internet > modem > router > switch (no uplink on switch) > all pcs. i got the server working (finaly) but all the 98s dont work.
ps. i disabled the dhcp on the router, put in a dhcp option (router)