

If you are using Outlook 2010 Home and Business C2R, you should uninstall it then log into the download site and download the MSI. If you don't want to edit the registry yourself, you can download and run this registry file: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\15.0\Outlook HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\16.0\Outlook If you are using Office 64 bit, check this registry key and create it if it does not exist. See 64-bit editions of Office 2010 for Microsoft's recommendations. Also, you cannot mix-and-match Office 'bitness' - you need to use all 64-bit or all 32-bit Office applications. There is no benefit in using Office 64 bit for "normal" users. Using 64-bit Office is not recommended unless you need large (2GB) file support in Excel or Access.

Using Outlook 64-bit with 32-bit Applications (In older versions of Office, the option is called Repair.) Select Quick Repair then click the Repair button.Find and select your Office or Outlook installation.Open Control panel, Program and Features.

If the affected program was installed after Office, try repairing the Office installation.
