Launch Registry Toolkit and click on the < Start Registry Defragmentation > link in the left bottom part of the window. To do this you should first click on the corresponding item in the right part of the window.
Note: To ensure proper operation of "Registry Defragmentation", you should be logged in as a system administrator either verify that you have equivalent permission to access the registry.
To defragment your registry, simply run "Registry Defragmentation", click "Go!", and when the process is completed click "Yes" to reboot the computer. You should do so immediately because any changes made to the registry after "Registry Defragmentation" has been run won't be saved.
Depending on your system configuration the optimization process may take some time.