DTweak Free is a free advanced tweaker and optimizing tool especialy designed for Windows Vista.
With DTweak you can
defragment disks and registers,
clean registry sistem,
tune computer performance,
optimize and increase the speed
of your Windows Vista system without manually modifying registers or ini files.

DTweak at the moment has a lot of features like Disk and Registry defragmenters, error scaners, user account control tweakers etc - for more information see Features section.
Anyway - we continue adding new features with every new release, and if you didn't see a needed feature in this release you'll see it in the next!