Drives admin share ($)

I am trying to share a folder between PC’s on an NT 4.0 network but for some reason when try to share the C: or D: drive using the $ sign admin share I do not have the sharing option on the menu unless I am logged in as administrator and, when I logback in as regular network user neither the share nor the sharing option is available.
I think this problem happened after installing the latest NT 4.0 service pack (6a)because I used to do this before.
Can anybody help me solve this problem to acomplish this task?
Thanks.

Manuel Rodriguez.