If two different browsers give the same problem, then the problem doesn't lie with your system. Either you're on cable Internet and someone on the same neighborhood hub as you has recently discovered the world of file sharing, or the sites themselves are overloaded. There's also a possibility of things being throttled now that the FCC's attempts to reign in such behavior have been struck down. In any case, there's nothing you can do but hope for the best, because the problem isn't with your system.
Up until recently I was able to stream video from the internet (hulu, cbs, netflix) more or less fine, not super high resolution, but not bad. Fairly recently (past month or so) every time I try and stream pretty much anything, the sound works fine, but the video is choppy and behind the sound. I can play a DVD fine and downloaded stuff also works fine.
I have an inspirion 1521 (2gb ram, running vista sp2). Internet should be plenty fast enough. Antivirus is up to date. I use firefox, but tested it and have the same problem in both chrome and ie. I can't think of anything that I changed when it stopped working.
So any help would be great! Thanks!