Determining Codecs

Gang, I've been looking thru posts for an answer to this question and can't find one;

I am running an NVIDIA 9300 chipset with Flash 10.1 Beta to take advantage of the hardware for decoding. I'd also like to take advantage of the hardware decoding and PureVideo HD for all the other formats supported by the NVIDIA chipset. Machine is 64 bit Win 7

I have PowerDVD 8 BD and Shark007 codecs on the machine. We watch Hulu and similar sites thru Media Center 7 via Playon. We also play DVDs, Blu-Ray, and local files. I have the NVIDIA driver set to "Use NVIDIA Settings" rather than "Use the Player Settings"

How can I tell, especially for streaming video (rather than files resident on the PC) just what is doing the decoding (the NVIDIA drivers, FFDSHOW, the PowerDVD codecs?). How do I force the system to use the Nvidia hardware? How can I tell if it is?

Thanks
TJ

Thanks Mike, I'm looking at the GraphStudio information. Looks pretty straight forward if I am just selecting and rendering a media file that is sitting on my computer. This may be a dumb question, but if I am connected to say, HULU and HULU is streaming a video, how do I select that video in GraphStudio to render?