If you’ve used the new Windows XP Mode feature of Windows 7, you’re aware that it allows you to save your login credentials for the XPMUser account it creates for you. However, what they failed to inform you of is that these credentials, although saved, are ultimately tied in with the computer name set up for that specific virtual machine.
That may be all well and good (and I do agree, it certainly makes sense), but what if you change the computer name within your XP Mode virtual machine? Well, the answer to that was made abundantly clear to me when I did that very thing (completely unaware of how credentials were saved at the time) just the other day – ultimately locking myself out of accessing any of the applications I had just finished installing in Windows XP Mode.
What happened was somewhat obvious once you look at the information saved in the Credential Manager for a little while; Microsoft Virtual PC was no longer logging me in automatically as the XPMUser – instead it was prompting me to enter the password, or specify an alternate account to log in as. The problem was, I had used a random password generator for the password and never bothered to write it down anywhere (because I figured that the Credential Manager was going to handle that all for me), so I had no idea what the password was and of course the Administrator account is disabled (unless you’re in Safe Mode) so I had no way of logging in any more!
What I did to remedy this situation was a bit old-school. I first changed the virtual machine settings and disabled the integration features so that I would see the boot-up process. As it started to boot, I hit F8 on my keyboard to get the Safe Mode boot prompt and I booted in to Safe Mode. From there I was able to log in to the Administrator account (no password) and then get in to the system and reset the password for the XPMUser account. Once that was done, I just had to reboot the virtual machine again (and reset the settings to re-enable integration features) and enter the new password for the XPMUser account (and save that information with the Credential Manager).
Now my Windows XP Mode virtual machine had the correct computer name for my LAN, and the Credential Manager was able to log me in automatically again when I used Windows XP Mode – yay!