OneNote is the new star of the Office Suite, and is included in every edition of Office 2010.  OneNote’s file format has been changed in the 2010 version, so here’s how you can still share your notebooks with those using OneNote 2007.

Convert your OneNote Notebooks to 2007 Format

If you open a notebook from OneNote 2010 in OneNote 2007, you may see this warning informing you that the notebook was created in a newer version of OneNote and cannot be opened.

To make your 2010 notebooks compatible with OneNote 2007, you need to convert them inside OneNote 2010.  In OneNote 2010, open the File menu; this should open to the Info tab by default.  Select the Settings button beside the notebook you want to use in OneNote 2007, and select Properties.

In the properties dialog, click “Convert to 2007”.

You may see a warning that some formatting, content, and history that is incompatible with OneNote 2007 will be removed.  Click Ok to continue.

OneNote will automatically convert everything in this notebook to 2007 format.  If your notebook is very large, this may take a few minutes.

Once the conversion is completed, you can re-open the properties dialog to see the change.  The format is listed as OneNote 2007 format, and you have the option to convert to 2010.  Your 2007 formatted notebook is still fully usable in OneNote 2010, but you may not be able to use some of the newer features in it.

Now that your notebook is in 2007 format, you can share it with OneNote 2007 users.  Here’s our notebook, the OneNote 2010 guide, open in OneNote 2007 after the conversion.

Conclusion

OneNote can be a great collaboration tool, and with this simple trick you can collaborate with those using older versions of OneNote.  Additionally, if you are currently running Office 2010 beta but plan to switch back to Office 2007 when the beta expires, then make sure to do this to any new notebooks you’ve created so you can still use them.