Before trying to understand how the registry works and how it is constructed let us understand what a registry is and how it slows down a system if it is not regularly cleaned by registry cleaner software.

The registry is the central database of the operating system and stores all the information that the computer needs to run. This information includes the hardware information of the computer, the user information such as which user is allowed to do what on the computer, and all the reference data about the software that is installed on the system. The operating system of the computer constantly refers to this registry, which has to scan through its files and keys to locate the information and feed it back to the operating system. If this list in the registry keeps on growing it will take longer to locate the information and so take longer to load programs in effect it will slow down the system drastically if the registry is too large. The registry needs to be compressed and cleaned with windows registry cleaner software from time to time to keep the system running smoothly.

Let us take an example of how the registry will be delayed if it is filled with useless data. When you click on the 'start' button windows immediately refers to the registry key labeled HKCUMicrosoftWindowsCurrentVersionPolicies Keys and determines what the current user is allowed to do. The registry knows this from its records by referring to the associated entries when the current user logged on with a username and password. While the computer is doing this verification you will have clicked on the 'programs' link and the HKCUMicrosoftWindowsCurrentVersionPolicies Keys are referred to determine how the operating system should react. When you click on a program you are clicking on a 'link', which is actually a shortcut to the program.

When you click on the link Windows refers to the HKLMSoftwareClasses Key for the extension ".lnk" which reads "lnkfile". Windows then looks for HKLMSoftwareClasseslnkfile which read "ShortCut" and it sees "NeverShowEx" = "" which means 'do not display file extension for this type of file extension'. Windows then looks to see what SubKeys are there and it finds a CLSID SubKey which points to "{00021401-0000-0000-C000-000000000046}". By the look of the Classid you will understand how many classid's there are in the registry. The registry has to go through all these serially. Here is where the time is consumed and the system is slowed. Each time you download something or refer to the internet the registry is updated and it grows.

It is important to constantly clean the registry of these redundant entries by using a free windows XP registry cleaner. There are many free pc registry cleaners and they all do a good job cleaning the registry. So download one today and tune your registry to make it more efficient and your system faster.