Outlook/Excel 2010 accessibility Checker

[lezawang]

Sorry this might not be 100% excel but there is a link to excel. I open Excel-->File-->Custom Ribbon -->All commands, and I can see Accessibility Checker there. I can added. I open Outlook and do the same thing but Accessibility command is not there. Both 2010. Why is that? I thought all same commands should be available for all applications. I have second computer with Office 365 and that command available in Excel and Outlook.
Any suggestion would be very much appreciated. Thanks