Yesterday, I posted about my practice of using the built in system image creation tools in Windows 7 and Windows 8 to create a backup of my system whenever I'm getting ready to upgrade.

Now, if something goes tragically wrong, I can just boot to a system repair disk, and restore the image, and I'm back to where I started. But let's suppose the install goes fine, but I find that there's a file I need to get to from my backup, but I don't want to restore the entire backup, just get that file.

The good news is that you can do this easily, because the system image is stored as a .vhd (or in the case of Windows 8, a .vhdx) file. And Windows 8 can mount a VHD as a drive, making it easy to access the files from the backup.

Just plug in the external drive you used for your backup, and find the WindowsImageBackup folder (should be at the root of the drive), and inside it find the folder matching the name of the machine you backed up. Inside that should be a folder that starts with "Backup" and the date of the backup. And finally, inside the backup folder is a .vhd (or .vhdx) file containing the backup of your system (you might see more than one .vhd(x)...if so, look for the largest one, as shown in the image below):

If you right-click that file and select "Mount" (as shown below) Windows will mount the VHD file for you, and assign it a drive letter.

I did have one instance where I got the error message below, and a drive letter wasn't assigned. But I was able to go into the Disk Management utility, find the drive, and assign it a letter, and all worked normally from there:

Once you have the VHD mounted, it looks just like another drive, so you can copy any files you may need and away you go (note that you may need to update permissions on some folders if the accounts on your current system don't match the ones under which the system image was created)!