If you are unable to log on to your Windows 7 or Vista computer by using a temporary user profile, then this article may interest you.
When this happens, you will usually get the following error message:
The User Profile Service failed the logon. User profile cannot be loaded
This issue may occur if the user profile was manually deleted by using the command prompt or by using Windows Explorer and if the “Do not logon users with temporary profiles” Group Policy setting is configured.
A profile that is manually deleted does not remove the security identifier (SID) from the profile list in the registry.
If the SID is present, Windows will try to load the profile by using the ProfileImagePath that points to a nonexistent path. Therefore, the profile cannot be loaded.
To resolve this problem open yourself, follow these steps:
Right click Computer > Properties > Advanced system settings > Advanced tab > Under User Profiles, click Settings > In the User Profiles dialog box, select the profile that you want to delete > click Delete > Apply/OK.
Next open regedit and navigate to the following key:
Right-click the SID that you want to remove, and then click Delete.
Log on to the computer and create a new profile.
Alternatively, you can simply download and use this Fix It 50446 from Microsoft given on KB947215. You may lose your data if you have not backed it up.
You may also want to check out ReProfiler. It is a freeware tool for manipulating user profiles on Windows 7, Vista, XP, 2000, Server 2003 & Server 2008. If you face an issue where you are unable to access a user’s data and settings, check it out!
You may want to see this post, if you receive an error message, Unable to log you on because your profile could not be loaded, please contact your administrator.