Virtual PC: Cannot restore machine from hibernate

I managed to find a solution: deleting the hibernation state file. This is similar to deleting hiberfil.sys when your computer won't return, although there is a Windows boot option to do this (press F8 during boot).

Here's how to do it for a Virtual PC virtual machine:

1. Navigate to the location of the virtual machine's settings file (.vmc file). In my case, it was in the same location as the virtual hard disk, under:

   C:\Users\[username]\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines\
   

2. If your machine had been hibernated last time you closed it, you will see a fairly sizable "Virtual Machine Saved State" file (.vsv). By deleting this file, you will delete the hibernation data, and the machine will boot normally.

   

If deleting the saved state doesn't work for you, fear not: I also discovered a way of easily accessing the data.

Open the "Disk Management" console, revealing the various disks and partitions on your system. You can easily reach it on any flavor of Windows by typing diskmgmt.msc in the Run dialog.

Once open, check the "Action" menu: you will see an option to attach a Virtual Hard Disk (VHD):

Hit Attach VHD, browse to the .vhd file, and it will show up as a disk in the Explorer. There it is: you can recover your data!