As someone who has had to live with low quality internet connections, the first things I do, before touching hardware, is to run a ping trace (I use pingplotter) and look at internetpulse.net. A ping trace will immediately fail if you have local to your machine/router/modem hardware trouble and so will a web query fail if you have local trouble, even if the Windows icon says that you are connected to the internet. If I have something like that then I will power cycle the nic (ipconfig release, ipconfig flushdns, ipconfig renew, or pull the cord or pull the USB wi-fi adapter out). If I can see the router but nothing else then I'll cycle both the modem and the router.
One nice thing about pingplotter is that it will show name resolved hops graphically so you can see where trouble may lie between you and the server. Unfortunately for me, my ISP is pretty good but the backbone operator they use is prone to having routing trouble. I think people really don't know how ugly the backbone looks even when you don't lose connections completely.
"No sadder words of tongue or pen are the words: 'Might have been'." -- John Greenleaf Whittier
"Do or do not. There is no try." -- Yoda
On planet Earth, there is a try.
Indeed, in a world and life full of change, the only constant is human nature (A is A, after all :P).
We old vets need to keep in mind those who come after us.