Updating Problems

While I was updating several cortexes and controllers, they would update most of the way then pop up with an error message for a second then the computer couldn’t find them any more. I’ve attached a picture of what the message said. How do I fix this?
Cortex update error message.jpg

A second VEXnet Upgrade Utility may be running in the background. Open Windows Task Manager with a Ctrl-Alt-Del. Select VEXnet Upgrade Utility in the Application tab and click End Task. Repeat for each instance of VEXnet Upgrade Utility.

If the End Task steps don’t work, reboot the PC. For reference, no more than one Cortex or one Joystick should be attached to the PC.