ripping to mp3 on WMP10

hi all, i just got a new computer with XP media centre on it, and media
player 10. i've been trying to rip some cds to mp3 format, but no matter
what settings i change in the options menu i am told that "Windows Media
Player cannot rip the track because a compatible MP3 encoder is not installed
on your computer" - which according to the windows websites should be a
standard issue thing with WMP10! i do not want to pay to get this encoder as
i should, by right, already have it!

The error code i get is C00D0FAA: Cannot rip the files, which ive done the
troubleshooting on (ie changing my options and deleting the suggested
registry key) and it has done nothing! Can anyone help? Is this problem
common?

Thanks a million!