You should use an ethernet cable to connect the two computers. It's faster
and easier, plus I am not shure that you can use parrallel cables to share an
internet connection.
Years ago, I had several standard RJ-45 cables laying around, but
needed a crossover cable. The local CompUSA sold 'em for about
$15-$25, a rip-off for sure!
This is how I have made my own crossover cables for years:
Open the cable away from the plugs, far enough to give you room to cut
and splice.
There are four solid colors, as well as same colors mixed with white:
solid green, solid orange, solid brown, solid blue, blue/white, green
white, orange/white, brown white.
To make a crossover, simply switch the wires with green on one end to
their orange counterpart on the other end. Don't change the blue or
brown wires. Be sure all splices are with plenty of wire to make good
connections, and the open wires have bben wrapped in tape well.
That is, cut and splice ONLY:
solid green to solid orange,
green/white to orange/white,
solid orange to solid green,
orange/white to green/white.
Now you can connect both PCs together using any standard plain-vanilla
10/100bT or 10/100/1000bT ethernet cards.