A virtual hard disk, often referred to as a VHD file, is a hard disk image stored in the form of a single file. These files are used for virtual computers (emulated computers within a host operating system). The format is used by a variety of applications including VirtualBox, Windows Virtual PC and the Windows Backup utility. Using the Computer Management console in Windows 7, it is also possible to mount a virtual hard disk file. Once the file is mounted, you'll be able to access and use it from Windows Explorer and it will act just like a real hard drive.
To mount the VHD file, you'll need to use the Disk Management utility. This is accessible by right-clicking on "Computer" in the start menu and clicking "Manage." Under the "Storage" section in the left-side pane, you'll see the Disk Management utility. Click on it and wait a few moments for it to start up. You'll now be able to see the physical disk drives installed on your computer as well as their partitioning, free space and file system information. Right-click on the Disk Management icon in the left-side pane and click "Attach VHD." ( See below image )
Click "Browse" and browse to the location containing the virtual hard disk file. Select the file to highlight it and click "Open." If you want to be able to modify the contents of the drive in any way, you should ensure that the box beside "Read-only" is unchecked. Click "OK" to continue.
The virtual disk drive will be mounted and now it will appear in the main section of the Disk Management window. It will already have a drive letter assigned and it will act in just the same way as a real hard drive. Now you can open Windows Explorer by clicking "Computer" in the start menu. You'll see the new drive appear.
If you want to detach the virtual hard disk drive, return to the Disk Management console, right-click on the disk and choose "Detach VHD." You will now have the option to delete the virtual hard disk as well. If you don't check this box, the virtual hard disk will simply be detached, but no data on the disk will be modified in any way. You'll be able to mount it again at any time by repeating the above steps.
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