Microsoft Office 2013 Portable Best -

Does not modify the host computer's system registry.

Most "portable" versions found online are unofficial, modified versions created by third parties using virtualization tools like ThinApp or Turbo. Important Considerations microsoft office 2013 portable best

LibreOffice is the most robust open-source office suite available. The portable version is officially maintained and optimized for USB drives. Does not modify the host computer's system registry