You can download the video from:

http://windowsmedia.microsoft.com/preview/Queen/Queen.asp

The press release for this event reads as follows:

To mark World AIDS Day, December 1, 1999, rock legends Queen and David Bowie have made an exclusive video available for free download here on WindowsMedia.com! For 2-weeks, beginning December 1, you can download a newly-produced video for the classic Bowie-Queen collaboration, "Under Pressure," featuring a remixed audio track from the new "Queen + Greatest Hits III" album.

The video is free to download, and you'll also have the opportunity to make a donation to the Mercury Phoenix Trust, an AIDS charity founded by Queen that has donated over $9.7 million to combat the spread of AIDS and HIV infection.