On a clean install of win2000sp4, BSP .86b500 played wmv files fine. Opened one using Media Player 6.4, got autodownload codec dialog, and then the dreaded grey screen on play. Worse, BSP also grey screened the video and played audio only from then on.
Loaded WMP 7.1, and it played the same wmv files fine, but no-go with BSP (or MP 6.4). Then installed wmp8 codes, wmv9vcm, even wmp9 codecs from Microsoft--STILL a no-go with wmv files and BSP. I did not want to install WMP 9.
Finally, read that the WMP9 run-time files can be installed separately from the player. They are a part of the WMP Format SDK Series 9 SDK, in a package named wmfdist.exe. I could not find wmfdist.exe available as a separate download (?). So I d/l'd and installed the SDK on a "test bed" at work, and then grabbed wmfdist.exe from it and executed that on my own PC. And, HEJA!, wmv video now plays perfectly on BSP.
I can only guess that the auto codec download of MP 6.4 at the beginning of the saga replaced existing wmv codecs with ones dependent on the WMP9 runtimes.
So, if your BSPlayer will not display wmv video, either install WMP9, or, as I did, the WMP9 runtime package wmfdist.exe. The WMP Format SDK Series 9 SDK in which it resides is available starting at:
http://wmlicense.smdisp.net/v9sdk/
You have to give them an email address to mail the d/l link to. Why? hey it's Microsoft, go figure.