If you're still having problems viewing the GameStar Halo movie in .ASF format, then I have a few suggestions. The first is that, if they are absolutely dying to see this footage right now, then both Mac and PC users should download the newest version of the Windows Media Player, installing it after uninstalling any previous versions. Second, it appears that there may be corrupt versions out there. I have only been able to view the .ASF file after downloading it from the Halo Network site.
Other than these few suggestions, the unlucky majority of Halofen out there will unfortunately have to wait until either it is converted into another, more common format or the original GameStar movie is released.