We have many people who report a "device not found" condition, when they plug the i1Display2 or the i1 Spectrophotometer into their computer.
We also get many people who report unusual readings when they run i1Match software in the Easy mode.

In both of these instances, the actual USB port that is in use can influence the results. Here's our recommendations on what USB ports to use, and why.
Although many people believe that all USB ports "are created equal", we've experienced enough exceptions to this to warrant this tech note.

For Best USB Communications, please follow these tips:

In Windows, USB device drivers are loaded on a port by port basis. Please check in Device Manager to see if the device listing for the i1 has an exclamation mark. If it has some alert indicator, please uninstall and reinstall the device drivers for that port.

Whenever possible, plug the i1 device into a USB port on the back of the CPU. These ports will have a more direct connection to the motherboard, than a front mounted USB port.

Avoid using any USB extender cables, as these can often cause a loss of signal and/or power to the device. This is particularly important with the i1 Spectrophotometer, as it uses the USB port for both power and communications.

Laptop computers often have USB communication issues that you might not see with a desktop computer. We often find that irregular readings on a laptop's USB port can be corrected by the use of a powered USB hub (a hub with a wall power adaptor connection).

MacBook Pro laptop computers also often benefit by running Apple's Disk Utility and repairing disk permissions. This is often necessary due to changes in the USB supporting software from Apple, after OS upgrades (these are often automatic).