If I put that error message on google I see it's been discussed in depth.
In short the user's profile is corrupt in some way so the log on looks like it's started as if new.
The most common cause is malware. You may want to visit the Cnet Spyware forum to learn more and see what scans to perform next. McAfee alone is not enough for today's pests.
HOWEVER if anyone used a registry cleaner, that's a fine way to damage a profile.
I have a 3 year old Dell Dimension E521 which has been fine. My McAfee security software expired a few days ago and I only bought a new package this morning, because.....
When I started the PC this morning it started as if it were brand new with the message - "Your user profile was not loaded correctly"- and there's no Windows Mail and no Outlook with all my business contacts and appointments etc. Also each time I restart it it starts again as if from new.
I've installed the new McAfee Internet Security but when I restarted the PC it was nowhere to be found.
Can anyone help with this?