Ok I don't know much about this.. But what I can suggest is...

For every computer you got disconnect all the wires and leave one mouse working for that comp. Then move the cursor to the upper left corner. Then unplug that comp and move on to the next comp. When you reach the last one and move it in the upper corner leave the mouse alone and plug the others in.

Might work. I dono how you would do this on start up.. maybe all over again who knows.