Eliminate slow start-up or shutdown speed and computer crashes by keeping your registry compact. Use Registry Defragmenter to optimize you registry and get rid of structural mistakes and corruptions. With compact and optimized registry you will be amazed at the speed your computer will perform. Registry Defragmenter will rebuild and re-index your registry to eliminate structural mistakes and corruptions. The Windows Registry constantly grows as data is added to it, but it never shrinks when data is removed. A bloated registry with a lot of empty space in it can slow down the boot time as well as performance of the entire system.