Windows Media Player won't download to M-240

Having trouble synchronizing Windows Media Player to my M-240. Reformated, tried to synchronize, got the following…“Windows Media Player cannot synchronize the file. The player might not support the filetype.” Is this a problem with Windows or my M-240? How do I fix this? Please help.

What version of Windows Media Player are you using?

I can’t find it in my programs list. Whatever it is came with my Sansa 'cause it wasn’t there before. When I bring up Windows Media Player it says  “Windows Media Player 10.” Hope this helps you help me. Thanks.