The 32-bit version of Office is the recommended option for most users, because it prevents potential compatibility issues with other 32-bit applications, specifically third-party add-ins that are available only for 32-bit operating systems. Using the 32-bit version of Office allows people to continue to use existing third-party add-ins for Office that are 32-bit.
Office provides support for the 32-bit version of Office programs running on 64-bit operating systems by using WOW64, a compatibility environment provided by the operating system that allows a 32-bit application to run on a Windows 64-bit operating system.
