Registry Cleaners

Registry cleaners are software designed to remove malware and redundant items from the Microsoft Windows Registry. Information regarding the Windows operating system, including the device drivers, SAM and kernel are stored in the Windows Registry. Registry cleaners scan and attempt to remove or repair items that may have been left from uninstalled software or other unwanted items. Registry cleaners may improve the overall performance of computers.

Advantages of Registry Cleaners

Manually cleaning items such as invalid entries, broken links, or missing file references would be time consuming. Therefore, registry cleaners were designed to automate the process and clean up any excess or invalid information that may slow the computer.

Specifically, some registry cleaners are aimed towards cleaning up the files that are left behind by outdated drivers and other software downloads. For instance, if the user installs an updated version of a printer driver, there may be some files in the old driver that are not removed when the new driver is installed. Those files may slow the computer. Registry cleaners are designed to remove these old files to improve the performance speed of the computer.

Use of registry cleaners have been made more desirable by adding functions that will allow the user to revert to the original state of the computer before the registry was cleaned. This function makes the use of registry cleaners more desirable. Individuals who download programs on a frequent basis find the restore function helpful.

Currently, registry cleaners are used because there is no other technology designed for this purpose. However, the .NET Framework platform does not use the registry for saving configurations and application settings. If computers migrate towards using these platforms then registry cleaners would become obsolete.

Disadvantages of Registry Cleaners

Over the years, many have contested the benefits of registry cleaners because much of the freeware is accompanied by malware or scareware. Scareware is software sold to consumers, but has little or no benefit. Much of this software is sold through marketing that is reliant upon the consumer’s perceived threat. Much of this type of software may also be associated with spyware or adware.

Registry Damage

Another disadvantage of registry cleaners is that they do not categorized errors by their severity. Thus, the user may not know what type of action to take to further resolve the issue if needed. Registry cleaners suffering from inferior design may not indicate to the user the effects of removing a program or whether it is still in use by another program.

If a necessary item is removed by registry cleaners, the system may become instable or the program may no longer function.

Malware Payloads

Registry cleaners have oft been the host for many Trojan viruses to install malware. Much of this occurs through website pop-ups and other types of social engineering efforts.


Much of scareware uses faux registry cleaners and advertising that “scare” the consumer to take action to purchase software based upon a false claim that the user's computer is infected. Many lawsuits have been filed against businesses that use this type of advertising and software.

Performance Benefits Considered Marginal

Windows NT, Windows XP, and Windows Vista currently use a registry structure with improved indexing and memory management. Computers operating on other or less modern Windows operating systems cannot handle a large registry without it adversely affecting the computer’s speed. Many experts recommend registry defragmenting over registry cleaners, because the documented benefits of registry cleaners is reportedly negligible.

Undeletable Registry Keys

Keys and values comprise the basic elements of a registry. Registry keys may contain sub keys and sub keys may contain sub keys, similar to folder structure. Registry keys have various levels of hierarchy and each hierarchy is indicated by back slashes. Data pairs are stored within the registry keys. These data pairs are called registry values.

Some problems cannot be repaired by registry cleaners. Some registry keys cannot be deleted because of the embedded null characters contained within the name. Special tools must be utilized to repair such problems.

Recovery Capability

Recovery of a corrupt registry is supported by Microsoft through System Restore or Automated System Recovery. However, a registry cleaner cannot repair an item in the registry hive that cannot be recovered by the system. Hives are sections within a registry. Most hives begin with the designation “HKEY”.

Malware Removal

Malware often poses a problem for registry cleaners to remove. Registry cleaners cannot effectively remove viruses, adware, and spyware. Often, if the registry cleaner removes a portion of the malware, because of the nature of the virus it may cause the system instability.

Rootkits may also go undetected by registry cleaners. Rootkits often hide information from other processes. Specialized tools may be employed to remove rootkits.

Application Virtualization

Registry cleaners are not designed to work with virtualized applications.