Chimel is right.  

I would start the computer in safe mode and see how it runs.  That gives you a clue too as to how much memory you're using with unwanted or unneeded programs.

Using MSCONFIG you can probably uncheck every box and it will run a lot better.

I would also run Malwarebytes in safe mode and see what happens.   Note if you install Malwarebytes the last screen offers a free trial of the premium version, take the check mark out before you click ok.