System Sentry 

System Sentry finds all corrupted, replaced, added, incorrect versions, changed dates of your system files and replaces them for you. This helps avoid the often unnecessary and frustrating task of reinstalling Windows or specific problem programs.
file registry errors

NT System Sentry 

System Sentry finds all corrupted, replaced, added, incorrect versions, and dates of your system files and replaces them for you. This helps avoid the often unnecessary and frustrating task of reinstalling Windows or specific problem programs.
file registry errors illegal operation