As already mentioned, Nero will allow you to convert videos but not rip a web stream. What I use and recommend for this purpose is:
* Net Transport
- Download manager that can rip just about any stream you throw at it. This is the one I use the most, but it's not free though.
* Ashampoo Clipfisher
- Freeware program with a nice interface that will rip stream from some of the most popular Flash video sites (youtube etc.), and it will even convert them for you if you wish. I really like it, even if you can't use it with just any stream.
* WM Recorder
-This one can also handle just about any stream you can think of and it's my second choice, only beaten by Net Transport. Why second choice? I just don't think the interface does it or you as a user any favours, as it isn't really as userfriendly as it should have been. If that doesn't bother you, this is the one to get...if you're willing to pay the ~$50 they demand for it.