Microsoft Office 365 Download Center Portable ((better)) -

Microsoft does not offer an official "portable" version of Office 365 that runs directly from a USB drive without installation

Install Office desktop on a USB drive (not truly portable, supported approach) microsoft office 365 download center portable

The Microsoft Office 365 Download Center Portable offers a convenient and flexible way to access Office 365 applications without installing them on a computer. The portable version is ideal for users who need to work on multiple computers, use public computers, or travel frequently. By following the steps outlined in this paper, users can easily download and use the Microsoft Office 365 Download Center Portable. Microsoft does not offer an official "portable" version

Note that even with an offline installer, the software requires internet access for the initial activation and periodic subscription checks (typically every 30 days). Microsoft Learn 3. Office Deployment Tool (ODT) Free Microsoft 365 Online | Word, Excel, PowerPoint Microsoft Software License Terms (Microsoft 365)

Using the Portable Version of Microsoft Office 365

• Microsoft Software License Terms (Microsoft 365).
• “Risks of Portable Software in Corporate Environments” – SANS Institute.
• NIST SP 800-83 Guide to Malware Mitigation.

While Microsoft discontinued this years ago, older versions of Office (like 2010) had a feature allowing users to install a "Click-to-Run" version on a USB drive. However, with Office 365, the modern equivalent is simply logging into your account on a new computer.