The solution is simple to delete a locked or used VHD in Windows 8.1 or 8!
If you have clicked a VHD file in Explorer (double-click), this action will directly mount the VHDs as a virtual disk! The VHD is in use by the operating system as a mounted drive!
If the VHD in Windows 8.1/8 is mounted, the VHD cannot be deleted too! (see image 1 arrow 1...)
If you want to change this, you must first eject the VHD via Windows Explorer. Then the VHD file can be deleted without any problems!
... The ejection of the VHD over the MS Explorer in Windows 8.1!
... Unmount (eject) the VHD over the disk management in Windows 8!
FAQ 209: Updated on: April 4th 2014 12:48