To change from a 32-bit version to a 64-bit version or vice versa, you need to uninstall Office first (including any stand-alone Office apps you. Tip: The 64-bit version is installed by default unless Office detects you already have a 32-bit version of Office (or a stand-alone Office app such as Project or Visio) installed.In this case, the 32-bit version of Office will be installed instead.This Microsoft office for mac is one of the best and successors of 2011 and it is followed by the Microsoft office for mac of 2007. Microsoft office for mac is a completely different version from the office for windows because it is a version which is totally based on the Microsoft Office productivity suite for mac os x.