|You may simply need to clean out your computer from accumulated dust. Just power it down, unplug it. open it, and blow out the dust with a compressed air can. Clean out all heat sinks, vents, fans, and anywhere you have a build up of dust.|
While it is open, look with a strong light to see if any capacitors are bulging, leaking, or burnt looking. If they are, replace.
You may have accumulated build up in Windows also. Run Disk Clean Up. Uninstall programs you do not use. Clean out browser (Cookies, History, etc.). Disable unneeded add ons. Disable most programs from starting with Windows (Run msconfig, go to Start Tab and uncheck all except MS & antivirus). Run Malwarebytes.
You have to be a little bit crazy to keep you from going insane.