You know there is data on the drive, but Windows is locking you out like a bouncer at an exclusive club. Before you panic and assume the drive is dead, understand this:

, the drive may be physically failing. Check if the drive shows up in Disk Management (Right-click Start > Disk Management). If it says "No Media" or "Unallocated," the hardware is likely dead, and you need data recovery software.

First, take ownership of the drive:

Nothing is more frustrating than clicking on your external hard drive, USB flash drive, or even an internal partition, only to be met with this dreaded popup: