"Incompatible Office products are installed on your machine" when opening Office documents or browsing OneDrive or SharePoint Site

You need to uninstall the stand-alone Microsoft OneDrive for Business 2013 sync client. [Edit: As noted in the comments, this issue is caused by any version of the stand-alone sync client, not just the Business version.] It looks like this in Add/Remove Programs:

The stand-alone sync client is the Incompatible Office product installed on your machine referred to by the February 10, 2015 update for Office 2013 (KB2920798) update. Your edition of Office 2013 came with its own OneDrive for Business 2013 sync client:

If you have one of the following versions of Office 2013, you already have the OneDrive for Business (formerly SkyDrive Pro) sync client installed:

• Office Professional Plus 2013
• Office 365 Enterprise E3
• Office 365 Midsize Business
• Office 365 Small Business Premium

This included OneDrive sync client is conflicting with the stand-alone client. As noted in the installation instructions, the stand-alone version is only meant to be installed with Office 2010:

The OneDrive for Business client can be installed side by side with Office 2010....Using OneDrive for Business alongside the 2007 Office system is not a supported scenario.

You may also need to uninstall the stand alone version of OneNote 2013.

Recently OneNote 2013 was made free, on a new Development Machine I had installed OneNote, however a few months later I realized that I needed the rest of the Office Suite on this machine. Installing from Media I opted not to install OneNote (because it was already installed of course!).

This appears to be an unsupported configuration.

To resolve it uninstall the stand alone OneNote 2013 install and then reinstall OneNote from the Office Suite in Programs and Features (in my case Microsoft Office Professional Plus 2013).