I have been using an HP 1600 laser jet. I installed an HP 8600 on my computer so I could print double sided copies. I want the 1600 on it also. The 1600 stopped printing. It looks as though all of the 1600 drivers, etc., are still on the computer. A test page works, but the 1600 does not print! The 8600 does print. Could the 8600 software have done something to the 1600? I want to use both of them. Thanks.