After Logging Into Windows You Are Stuck With A Blank Desktop

Had this happen when I tried to boot to a drive I had cloned.

1) Press CTRL+ALT+DEL and, if you can, go into the task manager. If not then the issue is something else.
2) File, New Task (Run…) and try to run something like services.msc. Pay attention to the path it is looking in. If it is not on the drive you expect it to be, continue. Otherwise the issue is something else
3) Reboot the PC using a PE with offline registry editing capability (Like Ultimate Boot CD or BartPE)
4) Open the registry in <bootdrive>\windows
5) Backup the registry!!!!
6) Look in HKLM\SYSTEM\MountedDevices
7) Locate the entry for \DosDevices\C: and rename it to a letter not being used. If the device no longer exists (like in the scenario above) OK to remove it.
8) Locate the entry for the drive letter the machine tried to boot to when having this issue. Right-click and chose "Rename"
9) Change it to \DosDevices\C:
10) Reboot. You should now get your desktop back. Windows may complain initially about windows not being genuine, but after a few reboot this went away. Likely because it could not find a component it needed to verify windows on the first reboot after the change