I'm looking at some MP3 players and you're right, some of them only work with Windows XP.
the brands were Iriver and Creative. Now I'm looking at the Iaudio players since they still work with Windows 2000. (and mac and linux, too)
I was looking at a Zen V. Not only do you need XP but you need WMP, too.
I forgot to add, I was on the Creative labs site and someone posted they returned a unit because it didn't work with any other OS except for XP, well the moderator got pretty snippy in his response. So, Iaudio is looking better and better.