Glary Utilities - The No. 1 Free, Powerful and All-in-one utility for cleaning your PC
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
AVG PC TuneUp - Peak performance for your PC. Keeps it going for longer. - More Speed Turbo Mode
Advanced SystemCare - Free optimization software & registry cleaner for Windows 10, 8, 7, Vista and XP. Advanced SystemCare Free to speed up PC, clean registry and repair system in one click.
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
Auslogics BoostSpeed - Auslogics BoostSpeed: Tune up Your PC for Peak Performance! . * Free trial lets you clean out junk files, enable several Live Speedup tools and run each of the 18 apps under All Tools once.