[Androcentric]

well i am on windows 7, and i am running horizon as admin. so why isnt it detecting it?

[Derek]

When every Horizon doesn't recognize my device, I try a different usb port.

[Michael]

Try restarting horizon. If that doesn't work unplug the transfer cable and plug it back in to a different USB port.

I had the same issue.

[Sam]

Try a different port.

Also, wait to see if the drivers are installed.

[iva1212]

This happen to me all the time i do all the thing everyone said and still not detecting my hdd