I’m sure this is documented somewhere but as I’ve just run into it I thought I would share. As I’m sure you know, Windows 7 (and IIRC Windows Vista) will generate a backup for you in a VHD format. When I was rebuilding my machine earlier this week, I decided to do a full machine backup and simply mount the resulting VHD afterwards to copy across any files I needed. Simples.
After performing the backup I ended up with two VHD files (corresponding to the two partitions Windows 7 creates by default on the disk) buried somewhere in the resulting folders. Job #1 was to make sure I could mount the “main” disk and extract files from it before flattening the machine.
Trouble was, on mounting either of the VHDs, the result looked something like this in Disk Management:
I was mounting the VHDs read-only. This turned out to be at the heart of the issue.
That done, it worked perfectly and I’ve happily extracted all the files I need as well as knowing I have a full backup to hand just in case.