Lexmark z645 and the disc is 640 but it does not work on your computer this is a printer?
Unless it states otherwise you can usually use most drivers in the z64x family.Go to Lexmarks support site and see if they have updated drivers. They also have the manuals there.You can also go into properties and see if you can renew the drivers.Go to the Device Manager and see if the printer is showing up or not.Can you see the printer in the computer and does it send the print job but doesn't make it to the printer? If so then if it's connected to a router via USB then it's probably a network problem, either the login or the connection is the problem. Trade USB cables.