im surprised that the vlc media player didnt work, ive used it in the past with win98 and it played everything.
you really need to consider upgrading to XP now.
the problems are only going to get worse for peeps with w98 and w2k.
lots of online applications are demanding newer/faster hw/sw platforms for accessing their media.
take google earth for example.
and of course there is no official support now, for w98 etc...