The User Profile Service failed the logon. User profile cannot be loaded.

We had the same problem on various workstations for people.  The Default Profile was the problem.  Check if the user has a profile in C:\users and if so this won't apply.  If not Copy the C:\users\Default profile from a working computer and replace the one in the computer giving this error.  You can overwrite everything.

Thanks for the quick reply. The workstation is in a workgroup. No other logon account was ever used or created except the one that was corrupted. I'll see if the user can copy the profile from another Windows 7 machine, but how would they copy it if no other logon is available. If not, is there a way to boot into the command prompt and reset the profile to factory default? Thanks.

User doesn't have another Win7 machine. Will try the restore point/Last known configuration. Thanks.

I updated my comment with some more steps.  The Last Known Good Configuration will not restore user profiles or files like that.

Just in case the F8 option doesn't work and yes the user does have another Win7 machine, how would you copy the C:\users\Default profile if I can't log into the broken machine? Can I get into recover mode and a command prompt?

Just saw your comment with the updates.

A few options exist here.  You can actually use Windows itself to do Safe Mode Command Prompt and as I recall USB drives (Thumb Drives) can be used in Safe Mode.  You would just need to identify what the drive letter was for that device.  You can then go ahead and issue the xcopy command to get it over from the flash drive.  

I would be curious to try the rename first on the users profile folder.

Great. Thanks. We'll try these options.

Yeh, not so sure I'd overwrite the profile with another from another computer as you might wipe out all the data under their existing profile.

Found another possible solution too from Micro$oft:

https://support.microsoft.com/en-us/kb/947215

I respectfully disagree with the request to delete this question.  The OP was provided various potential solutions by various experts.  Myself included provided links to several articles that discuss potential fixes as it relates to this particular error code. The OP didn't report success in those operations does not infer that the solutions offered wouldn't be a benefit to the OP or to the community as a whole and could provide troubleshooting steps to those with similar errors and steps that would not require duplicating in additional questions on EE that may be fixed with said steps.  It would also allow for someone to point out they attempted solutions provided by the experts here and were unsuccessful allowing for those experts to identify other potential solutions or areas of troubleshooting.  

I appreciate the chance and privilege to respectfully disagree and would request credit to be split by those that provided articles that articulate steps to repair the error and articles that support fixes for that error.  Not just for myself but Rob also provided a possible solution and link to the OP's request.