Files like WMV and WMA that are on my own computer play just fine, it's only things on the Internet that are an issue...does that rule out drivers?
The only driver it would not rule out would be the hardware device that connects you to the network, but that is rarely a problem, although I believe there have been rare instances where it was. Just make sure you have the Ethernet (if you are using that) or wireless network devices with their latest drivers and you are okay. I cannot imagine a misconfiguration of those devices either.
One thing to rule out hardware on ONE computer is to temporarily connect another computer in your location to the same router and see if the stream is the same in terms of low quality. If it works well, suspect the first computer to have a potential hardware device software/misconfiguration problem. If both computers show the low quality, the problem is on the other side of the router (network). This step-by-step elimination process is how many problems are traced/tracked down.
Did you try the file downloader yet? This first downloads the streamed media that is causing you a problem to your computer. You then play it something like VLC media player to see its quality.
Also: I do not know what your file type is, but you might try using VLC media player for everything, both as a standalone and as a plugin to your browsers. VLC MP has just about every codec under the sun (plays nearly every file type) and its developers are constantly improving it. Try configuring Chrome to make VLC plugin play that file type. If it's Adobe's stuff, that will be sufficient too.