High RAM usage in Windows 11 is often normal due to modern memory management. Windows treats RAM as a resource to use, not conserve, preloading frequently used apps and files via Sys Main (formerly Super Fetch) to improve speed. This cached data appears as 'in use' but is reclaimable, so high usage doesn't indicate a problem.
Having more RAM allows Windows to cache more, improving multitasking and responsiveness. Only when experiencing slowdowns, crashes, or low-memory alerts should users investigate via Task Manager's Processes tab, close unnecessary apps, restart to fix memory leaks, or disable startup programs. Third-party memory cleaners are ineffective and can slow performance by forcing data to the page file.
Disabling Sys Main is only advised on older PCs with mechanical drives where constant preloading causes sluggishness; otherwise, it's beneficial and should remain enabled.
Source: Engadget · Summarized by HeadlinesBriefing