СCleaner (formerly Crap Cleaner) is a free computer program which is used for cleaning invalid Windows Registry entries or potentially unwanted files and optimizing overall system performance.
Glary Utilities is free for non-commercial use software. It is designed for configuring and optimizing operating system by means of special tools used to speed up and control your PC.
MiniTool Partition Wizard Home Edition as a free partition manager offers you to perform many operations with your hard drive such as creating, deleting, formatting your disk partitions, and more.
Advanced SystemCare (formerly Advanced Windows Care) is a free package of various computer tools for optimizing, tuning, error control and improving overall performance of your operating system.
Windows Doctor is an advanced free program that is aimed at optimizing OS on your computer in case it starts running slowly.
EaseUS Partition Master Home Edition is a free tool that let you manage your hard disk and perform any operation with its partitions with ease: creating or deleting partitions, formatting, and more.