Home Network: I need help!!

The hub is in. The computers are connected and configured. One of them is an NT 4_O. The other, a dual-boot [Win98 and NT Server].
The problems: (a) Win98 sees NT on the Network, but NT doesn’t seem to see Win98.

(b) Win98 is not letting me enable “Sharing” its C drive by rt. clicking on it. [“D” drive is my NT Server installation] Help!!!