DUN Don’t!

On a win 98 SE PC, the Dialup Networking dials, negotiates and connects to my ISP. Using WINIPCFG I can see that an IP address was assigned. It all looks OK until I launch any application that uses TCP/IP. These apps crash immediatly. Ping, Tracert and browsers all crash. I took out DUN and reinstalled it. I used system file checker to look for corrupt files. All were OK. At one time, Shiva had been installed to access a corporate LAN and this problem seems to have cropped up after deleting Shiva. Any ideas?