As Ben says, OneNote 2007 can be used with or without Office. It doesn't
need Office at all.

The newer the version of Office that you have installed then the more
integration with OneNote you get (Send to OneNote, Outlook and OneNote can
swap notes and tasks etc).

Do you need OneNote 2007 to talk to Office 2000? I doubt they would talk
much.

If you don't need any Office integration with OneNote then you'll be fine
running ON2007 by itself.

--
Regards

John Waller