Try this:
Open regedit and navigate to the following key:
HKLM/SOFTWARE/Microsoft/Windows NT/CurrentVersion/ProfileList/<profile id>
Go through the <profile id>s and look at the 'ProfileImagePath' to find out the account's ID.
You may find that you see this same entry twice - <profile id> and <profile id>.bak. If this is the case then compare the two. You may find the ProfileImagePath for <profile id> is pointing to c:\users\temp. If this is the case then rename this key to <profile id>_old and rename <profile id>.bak to <profile id>.
This is only one of the causes of this issue. Permission issues on the account's folder, or in the registry could also cause this.