I downloaded Baku form download.com and installed it after reading their descriptions. I run a scanning without changing any settings.
After the cleaning it showed me that it saved me around 5 GB space on HDD.
But all went wrong, outlook not works and several windows errors. Even there are no items in All Programs tab in start menu!!!!!!!!!
A system restore saved me. I would suggest you to use Ccleaner instead. I have been using it from 2 years. It is very good and will not harm your PC.