What, exactly, do these system optimization products say they will do for your computer? I would avoid them unless you care to list some here and get recommendations from forum members on a specific product. Some of these products can do more harm than good.
You can keep your system optimized with free tools, some of which you already have on your Windows system such as Disk Cleanup and Disk Defragmenter. And, there are some good freeware tools such as
CCleaner, which I highly recommend. Many technically-savvy computer users use a disk defragmenter other than one that comes with Windows, such as
Auslogics Disk Defrag or
Smart Defrag from IObit or the recently released
Defraggler, from the same people that make CCleaner.