Julian,

try doing a "repair" from the add/remove programs. If that doesn't
work, try doing a reinstallation (uninstall/install). There is no "send
to onenote" addin for 2007--that was for 2003.

make certain you have the original product keys that MS emailed you if
this is a trial...if you don't, you will be unhappy if you try to
reinstall and OneNote doesn't work.

erik