Quit MonacoEZcolor. Connect your colorimeter directly (not through a hub!) to an available USB port on your computer. Ensure that the port is working with other USB devices. If you do not have a port available, temporarily disconnect a printer, scanner, or other non-essential device and plug the colorimeter into that port. Restart MonacoEZcolor and try to build a monitor profile using the colorimeter.
 

Restart your computer with the colorimeter unplugged.

Right-click on "My Computer/Properties/Device Manager"

Look under "Universal Serial Bus Controllers" - if you see any items with an exclamation or question mark next to them, right-click and delete.

Restart your computer.

Launch MonacoEZcolor, select the Monitor branch.

When you get to Step 2, plug the colorimeter in and click the Next arrow. MonacoEZcolor will manually search for the device. If the program does not see the device at that point, try switching to another port.

If you have another computer available, try the colorimeter on that machine to see if the device is recognized.