If you want to run more than one Gnutella servent at once you will have to make sure that the two programs are using different ports. To se the port Xolox uses:

'Tools' > 'preferences'

click on the 'network' tab

click on the 'advanced' button to reveal the force IP controls.

Fill out the boxes.

Note that this is probably no something you should be bothering with as a self proclaimed computer illirterate. I would recomend just simply using only one program at once.