Office 2021 or Microsoft 365 requires SSE4.2 instruction sets and 4GB+ RAM. Office 2013 runs on a potato with 1GB RAM. For netbooks or thin clients, 2013 is the last viable version.
LibreOffice is the most popular completely free, open-source alternative to Microsoft Office. microsoft office professional plus 2013 portable 2021
You can enable offline editing, allowing you to work on your documents even when you lose your internet connection. Summary Comparison "Office 2013 Portable 2021" (Cracked) Microsoft 365 for the Web LibreOffice Portable Cost Free (Illegal) Free (Official) Free (Open Source) Installation Required No (Runs from USB) Malware Risk Extreme Security Updates None (Discontinued) Automatic / Continuous Offline Functionality Conclusion Office 2021 or Microsoft 365 requires SSE4