ip\release renew problem

(The dns sever is working with other computer 2 win98 1 xp 1 2000 and 2 random computers at any one time. so the server is not the problem.)I am working on a win 98 computer that can not relese the ip address that it has (win defalt) i have it hooked up to a dns sever. i have set the defalt gate way also.(have also tryed with out it.) have rebuilt the tcp\ip by remaking it in the reg. also have have put 3 diffent network cards in it. tested the cable that it is hooked in to. ran norton windoc,sfc,virus scan, reinstalled windows over top. updated windows components(files). uninstalled and reinstalled all network components and probly alot more that i cant think of right know. help would great.