There are a few ways you can tell if the computer is not recognizing the ActivHub:
The red light is blinking.
There are no lights blinking.
“ActivHub” is not listed in the ActivManager.
First, ensure that you have the latest version of ActivDriver installed (see article 10902 on the Knowledge Base). Reboot the computer with the ActivHub detached from the computer. Plug is back in once the computer has loaded. For Windows users, check Device Manager to see if the device driver needs to be updated (see article 10394 on the Knowledge Base).