Ashampoo WinOptimizer 6
This all-in-one tuneup tool includes just about every optimization feature you can imagine. Whether you're looking to clean your Registry, clear out unnecessary programs that run on startup, undelete files, defragment your hard disk, or perform a simple, one-click optimization, you'll find it in Ashampoo WinOptimizer. And you'll find a lot more as well.
Ashampoo WinOptimizer digs quite deep into your system, and finds tweaks that other optimizers miss. For example, when you have it tune up your startup, it doesn't just check for unnecessary programs, as some other optimizers do. It also looks for services that don't need to be run, such as the Tablet PC Input Service. If you don't have a tablet PC, you don't need this service, yet frequently Windows programs load it on startup.
All the modules are well-integrated and easy to use. There's also a handy backup feature that lets you restore the state of your system if you make a change you'd like to roll back.
At $50, WinOptimizer isn't cheap. But if you want an all-in-one system optimizer that does a superb job, you'll find it worth the money.
Note: The program comes as a ten-day trial, but you can turn it into a 30-day trial via e-mail contact.