Use 2 Ethernet cards in the master comp 1-B/Band 1-slave Computer.
1- card in slave comp.
Use a cross-over cable from card in master "scnd one not connected to B/Band" to the card in slave comp. (Hope that makes sense)
Download for free a prog called ANALOGX of the net (Proxy server).
Follow instructions given in prog to the letter.
Away you go.
Max length of cable 10m.
If you need longer distance, will prob have to look at wireless.