Unable to Index OneNote

I cannot index Microsoft OneNote 2010. I specified the ".ONE" extension as an additional file type and re-indexed without success. I have tried the various search options (content, names, etc.) for the relevant folder where my OneNote files are stored.

I was able to index OneNote files during a trial period about 45 days ago. I uninstalled X1 after the trial but realizing my mistake I recently purchased X1 8.0.1. MY OS has been Windows 7 during the trial and after my purchase. I understand that the viewer will not work with OneNote. I would appreciate any advice for indexing and searching these files.

Thanks

---