I own two up to date computers with windows 10, with fairly different hardware, on both of them, windows fills the ram (99-100%) over time, usually after a month of run time. The first uses a hard drive; the second uses a SSD with low capacity + a hard drive.
When the ram is full, my programs are extremely slow and often freeze. When that happens, disk use also reaches 100% most of the time. I've found a temporary way to make my system usable, that is to launch a very ram intensive program multiple times, such as a video game, after leaving the computer running and closing the process, I have more ram available, and the computer is again usable.
Ram use and disk space on the task manager don't add up as you could imagine. This isn't due to malware; this is purely due to windows mismanaging ram.
Windows is using ram I don't want to be used, and I would like to make sure every unused ram is not used without my approval.
Changing the OS, hardware, or shutting down the system often aren't options for me.