NT Registry Drill removes invalid entries in Registry The Registry Drill is the most in-depth Registry utility available today. It goes through the Registry character by character searching for any possible errors. A blank Key, a pointer to a not existing Key, a non-existing file, invalid characters, and more.The Drill has two main components, the Quick Drill which quickly searches the Registry for 15 different possible types of errors that other Registry cleaners do not.The Deep Drill goes through the entire Registry slowly and carefully. looking for more than 50 different kinds of errors. The Registry Drill's help file walks you through any repairs you may need to do and carefully explains what errors found may be valid. It explains what why a Key is invalid and what information is missing or wrong.