RTO, excuse me for asking, but is your machine running continuously? Doesn't it recover from its slow down when re-booted?
Something not right if it doesn't. Check your Task Manager for a "Leaky App" that's using up your RAM. They are about and they're usually freeware or shareware.
Right-click the Task Bar. left click "Task Manager", on the tab "Process" under Mem Usage look for an application where figure is slowly increasing and identify the Process or Application.
Consign it to Room 101!
