For What Is Compression Intended

The specialty of the operating system is that when a key is deleted from the system registry, in fact, it is not truly deleted, but only marked as deleted. This is done to speed up the work with the registry. If the key is only marked as deleted but remains in the registry, we can get a gain on time. In other words, the operation is executed much faster.

However this mechanism has a drawback. Deleted keys that remain in the registry do not reduce the size of the registry. Information about deleted entries can remain in the registry for quite a long period of time.

Deleted keys that remain in the registry is just one of the problems that can be eliminated with the help of the Registry Optimization tool. The registry may contain other redundant data, which can cause an undesirable increase of registry size. In such cases, compression can considerably reduce the size of the registry on disk.

Registry compression is effective mostly for Windows XP and the earlier operating systems.