Disk is powered on, but computer no longer sees

Hello

Here is how you go to fixing this problem. Just follow these steps and you should be set. Go to:

Control panel
Administrative tools
Computer management
Storage
Disc management

Now you should be able to see your drive in the schematic below. Now right click on the drive and choose to change drive letter and paths.

Now just assighn a new drive letter to the drive, restart and you should be set. Hope this can solve your problem.

Best regards
Andrea