A registry optimizer is a piece of software that finds and repairs errors in the Windows® registry. There are many programs available that perform this function. Oftentimes, they are even available free of charge.
The Windows® registry is the portion of the Windows® operating system (OS) that stores program associations and settings. Among the things it determines are what a particular file type is and which program should open it. The registry also is used to store information about the software libraries included with some programs, and which of those supporting files the programs require to run.
As a result of the many settings it contains, the registry is a very complex group of operating system components. Whenever the Windows® system is utilized, changes take place in the registry to reflect such use. The registry is updated anytime programs are installed or removed, when Windows® is updated, and when the user alters a setting in the control panel. This results in a great number of registry modifications that, in turn, can cause entries to reference invalid file types or file locations; some of these out-of-date entries can lead to performance slowdowns, system errors or instability.
While it is possible for a user to manually edit the registry, its complexity makes that a daunting task, at best, and can render a computer unusable, at worst. A registry optimizer, however, is programmed specifically to look through the registry and correct any errors. This is the case regardless of what programs have been installed and what types of entries they have made in the registry.
A registry optimizer is usually simple to run, and most of them operate in a similar manner. Depending on which one is obtained, there may be specific settings the user can choose in regard to which types of errors to search for or how they should be repaired. When launched, the registry optimizer will scan the Windows® registry and display a list of problems it discovers; it is not uncommon for this list to contain hundreds or thousands of entries. The user can then choose to solve each issue individually or have the optimizer fix all the errors automatically. The most common method of repair is to delete the obsolete entries.
Though not required, re-running the registry optimizer again after repair of the registry can uncover even more issues. This occurs because the first registry repair usually results in out-of-date registry entries being deleted, which then causes any other registry keys that point to those entries also to become obsolete. To ensure the registry is fully optimized, this scan-and-repair cycle can be repeated until the scan reveals no problems with the registry. It also is possible to make use of multiple registry optimizers; in case there are registry issues one program does not report, they may be detected by the other.