If the computer has OneNote (any version), double-clicking a .one file from your USB drive will open it in read/write mode. You can copy the file back to your USB drive as a backup.
Microsoft OneNote Portable refers to versions or setups of OneNote that can be run without a full installation on a Windows PC — typically from a USB drive or as a standalone app. Common approaches include using the official OneNote apps (OneNote for Windows 10 / OneNote (Microsoft 365) / OneNote for the web) and portable wrappers or third‑party portable packages that allow OneNote-like functionality without installing system-wide components. Official Microsoft portable distribution for desktop OneNote is not provided; portable solutions are workarounds. Microsoft Onenote Portable
provided by Microsoft. Microsoft OneNote is designed as an installed application or a web-based service that relies on system integration and cloud syncing. Microsoft Support If the computer has OneNote (any version), double-clicking a
Log in via any browser at OneNote.com. It requires no installation, is always up-to-date, and syncs perfectly. Common approaches include using the official OneNote apps
on a thumb drive) and how you can still take your notes anywhere.