I beleive your problem is a networking issue. Have you made any changes to your network settings?
Try reinstalling your drivers for your network card or modem.
If that doesn't work try to redo your network settings by rt clicking on your network neighborhood icon and choosing properties. Make sure that you have the win98se disk with you. Go to the protocol which you are using. Probably tcp/ip and remove it. Reboot and open the properties again and click add choose protocol and click on tcp/ip. Reboot and cross fingers. ;)
Hopefully this takes care of the problem. If it doesn't please reject and tell us what happened.
Thanks and good luck.