I have the same problem. I just purchased a new Dell desktop computer and used the Easy Transfer process to copy my old computer's files and user profile to a WD external hard-drive, and then to my new computer. Now when I boot up, shut down, or hit CTRL+ALT+DEL to launch the task manager, I get:
LogonUI.exe - No Disk
There is no disk in the drive. Please insert a disk into drive
I can click "continue" twice and the system will continue on and do whatever task I've selected, but its annoying.
In addition, when I leave the computer on for a while and then return after a few hours, I can't get the computer to respond. I have to do a hard shut down and then reboot. I'm guessing that these issues are related but I don't know.
Any suggestions? I tried creating a new profile and was able to launch that profile without seeing the error message (suggesting perhaps my profile is corrupt) but I saw the error message when shutting down the computer from that profile.