The art of MS Paint drawing is a dying bread but it is much fun
ok, if the setup up to the modem works for 1 computer then the 2nd scenario is definatly possible. Simply check your modem if it has 2 ports like the one your XP computer is currently plugged into, then simply plug the other computer into the other jack. If not, you will need either a router or a switch. For only 2 computers it is probably more efficient to go with a router as it will also allow you to create a network more easily if you wish (technicalities on how switches work... they
can be slower).
The only change that is made is the cable from your xp comp and the other comp plug into the router. There will be a port labelled
in or
wan or something to indicate the input of internet and plug a short ethernet cable (router will likely come with one) from this port to the port your xp computer was plugged into.
Now your modem sends internet to the router which will then distribute it to the 2 computers connected to it.