Try doing a System Restore at boot using a restore point dated before this error to see if it fix this. You can delete the user profile, If you do not want to repair it and create a new user account . If this still does not work for you, then you will be left with the option of doing a clean install for your Upgrade or Full version of Vista or Windows 7.
You can also refer to the article for more details:
Hope it helps you
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