No Share option

It's quite possible that you don't have the sharing portion of Windows installed on your computer.

Go to add and remove software and see if you can install it from there. You will need the CD.

Good Luck

The solution to this is in the configuration of your network neighborhood. If you right-click Network Neighborhood, and select properties, then click "Add" which will appear below the list of network components that are installed. You will then have four options:"Client", "Adapter", "Protocol", or "Service". Select "Service", and click Add.
You will then have two different file and printer sharing options, and one other option. Select "file and printer sharing for Microsoft Networks" and then click "OK".
You will then be asked to restart your computer. Do so, after that, you will be able to share files and printers.

Before I received the third answer today I removed file & print sharing from the properties and then tried to add it again.
I got an error like "you need adminstrative priviledges". This box is on a peer to peer network of Win98 machines. No server, wide open, no administrative nothing. I installed poledit.exe on the box and discovered that the previous user had removed the file and print sharing option from the registry. That allowed the few things he had shared to remain, but took away the option to share anything new. I cleared one check from one box in poledit and everything was as it should be. Thanks to all of you who tried to help me, it was certainly appreciated.