Deleting a Virtual Hard Disk [Windows 7]
Before you proceed, be sure to take a backup of files you have in your virtual HDD. (if needed)
Open Disk Management by typing diskmgmt.msc in the RUN command. The Disk Management window will list out all your hard disk drives. Right-click the Virtual Disk you want to delete and choose ‘Delete Volume’. You’ll be warned that the action will permanently delete files in that Virtual Drive.
After you’ve delete the partition, the disk space will be unallocated.
Now, right-click ‘Disk n’ (n is the disk number associated with the virtual disk you are deleting) and click ‘Detach VHD’.
A new window will show you the corresponding *.VHD file, also allowing you to delete the *.VHD file after detaching. If you no longer need the VHD file, click the checkbox that says ‘Delete the virtual hard disk file after removing the disk’ and click OK.
Your virtual hard disk and the associated *.VHD file has now been deleted!