so i currently have 16gb of ram (4x4gb) in my gaming computer and when i leave the computer overnight to leave it download some big games, and after a while when i check on the computer it becomes really laggy on the desktop, can't even open any windows properly and shows that i have 99% of RAM usage, even though i didn't do anything and i think downloading games won't make my pc THAT slow.. and there are some times when i get fps drops in games, because my ram usage is like 15.8gb which is 99% as well, and it is really annoying. this problem appeared like a few days ago, and i upgraded to windows 10 as well, so there should be no viruses.