If you are using Window Vista machine like me, TweakVI is an absolutely indispensable program for tweaking and optimizing system. It is very useful to protect my privacy and speed up my Vista system, because of TweakVI creates effective features to clean registry, manage hard disk, optimize RAM, restore system and so on. Also TweakVI provides another helpful function that tweak hundreds of hidden features of Windows Vista and customize machine to my needs. I used it to easily customize and enhance the looks and feels of my Windows Vista.
The main application of TweakVI together with many plugins is available completely for free, but user need to subscribe and then download more additional plugins to have more and powerful features. That is unsatisfactory for me because many real useful applications are locked.