Check your browser (Avoid IE like the plague if you can avoid it, some sites require it based on ActiveX components but the overwhelming majority do not), check your browser add-ons and disable any/all you do not use consistently, clear your cache & cookies and check how many background processes/apps you have running at the OS level. Computers are not unlike cars in that you need to maintain services like oil changes with the occasional radiator flush, fluids top offs, etc.
In general, Comcast is pretty reliable and is definitely the best provider in the area but that’s not saying much when the only competition is the horrifically bad CLink.