Ok so I have a windows 8 64 bit machine. I have a xerox personal scanner as well as a dell 2330d printer. My issue is that the scanner only works if i have it plugged into one of my usb ports on the front of my machine and will not work on any that are on the back of the machine. As for my printer it works on either one the front or the back. I have plugged the scanner into everyone on the back and still doesn't work but as soon as I plug it in on the front USB it works! I would like to be able to plug both plugs into the open available USB ports on the back of the machine but only the ports on the front work for my scanner! How can I fix the back ones to work with my scanner and why is it that only the front ones work with it and the back ones do not?