Vista - User Folder Hidden

This morning I brought my PC out of Sleep mode to find that when I logged in
all my settings and files where gone.
When I opened Explorer to the C:\Users folder I couldn't see my User folder.
After logging out and logging in on the Administrator user I found that the
User Folder for my user had become a 'protected system folder'.
I tried using the DOS command 'ATTRIB' to remove the Hide attribute but it
failed.
After that I tried a couple of things, one of which seems to have worked:
1. I changed the Username to a new Username, however the folder name did not
change.
2. I explicitly set the 'Local Path' in the User Properties
3. I enabled Explorer to see both hidden and protected system files and
folders

How do I reset the folder and subfolder/files attributes back to the way
they were?
Any ideas as to how this might have happened?

Best regards,
Spike