net work newbie question

I dont know squat about networks But I have a microstar board that has the pc to pc usb network
The primary is win 2000 pro and the second is a laptop with XP pro..
Software for network has been installed on both. I used the primary as the server once before to a 98 computer and all went well.
Trying now with the laptop I can see the laptop, but the laptop cannot see the primary.When I say that I can/not see it means I have access to the files on laptop but I cant see anything on the primary.
I goto map drive and the computer is shown under browse but I cannot see anything on the other computer.
When I hit properties I get a message that says that I dont
have "appropriate access rights for this server.For more info Contact the administrator. Well since he and I are on the same name basis I asked him... Well he dont know. The primary was used as my internet connection
since new (dialup 18 months). I have shared individual folders on the primary before as I have done now, but I am wondering if I may have set something over time to not let the primary share at all. I know that shares are not a good plan on the internet and all. any help would sure be appreciated. More info is just a reply count away.

You Dont Want To Be The Last to Know Anything.