Edgeport/8 will not install

I just purchased an edgeport/8 to replace a 4 that was failing often. I would have to disconnect its USB and reconnect. I am running XP on an older Gateway. I uninstalled the 4 and then loaded the CD for the 8. At first I could not get any installation either through the wizard or through control panel add new hardware. I finally somehow got the 4 instances of edgeport to show but only one pair of comports. Starting and shutting down windows or unplugging and inserting the USB cable all give the same result. Windows cannot find the installation files. I was able to reload the 4 with its CD

Do the attached instructions help?