Click "Tools" and click "Options."
Click "Network," "Streaming Protocols" and check the box next to all listed types. Press "Apply" and "OK."
Re-enter the URL in full (including the "http://") and press "Enter" to access your chosen media, circumventing the syntax error.
No big differences have been found between Win7 RC and Win7 RTM.
There should be a lot of bug fixes and general optimization of the core components. The RTM has no watermark and has more stability performance and a general "finality". I'm still using the RC. It works perfectly fine, has all the features that I've read the RTM version has, so I haven't bothered to change yet.