Assume that you try to open a folder that contains no .onetoc2 file in Microsoft OneNote 2010. In this situation, OneNote 2010 opens the folder as a notebook.
To resolve this issue, follow these steps:
Apply the hotfix package that is described in Microsoft Knowledge Base (KB) article 2523130. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2523130 Description of the OneNote 2010 hotfix package (onenote-x-none.msp): April 26, 2011
Enable the hotfix package. To do this, follow these steps:
In Windows 7 or in Windows Vista, click Start, type regedit in the Start Search box, and then press ENTER.
If you are prompted for an administrator password, type the password. If you are prompted for confirmation, provide confirmation.
In Windows XP, click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then click the following registry subkey: