Clean Center is a good tool which will let you clean your computer and make it faster by freeing space in your HD.
Its easy to use and intuitive interface will lead you throughout the whole process, so you will have no problem at all.
It also includes a wizard, so if you don't know what to do when you find some files, it will help you.
Furthermore, the results during the tests have been good, so it becomes a good choice.
15-day trial version