Vista - Help!!! Windows Media Player 11 Vista 32 bit

I am unable to stream videos from a course site. Everytime I attempt to watch this streaming video my computer locks up at the buffering stage. My download speed is 17 mbps. I can watch cnn and youtube videos like that, but when there is another screen (small box) that has to open....it doesn't. In fact, it brings me down to limited connection and eventually kicks me off line. The weird thing is on the bottom of this black screen it says that I am streaming at 3.01 kbs. I have tried for months to figure this out and I can't.....I don't know what to do. Please help.