Windows Defender manages Antimalware Executable. You may assign any process name suspected of being malware, but it's your responsibility to confirm the correct paths. True
It's normal to notice increased RAM usage when you add more memory. You'll likely still face the same issues later on. Your system remains the same; only you change. The high usage doesn't mean programs are starving for RAM—they need it for speed. Caching operations helps, which raises demand. Turning off SysMain or prefetch can reduce usage, but why did you purchase RAM in the first place? It might be a waste if you never use it.
Ah ok! I don't have high hope either but having a clean install of Windows will help me get rid of old apps that I don't use. In the same time, I would like to have your opinion on one of my question posted up there: why does my system slow down when I download a game? Thanks!