Best windows 11 upgrade tool from an old Windows 10 PC

Flyby11 is a lightweight open-source tool that serves as a practical windows 11 upgrade tool, allowing you to install Windows 11 without creating a bootable USB drive, though it requires patching the Windows 11 ISO to bypass hardware checks.

It allows you to perform an in-place upgrade while keeping your files and apps intact, but using this feature requires downloading and modifying the official Windows 11 ISO file.

First, download the software from the official website. Unzip the ZIP file, then right-click the software and select Run as administrator.

Click to select the Windows 11 ISO, then click “Repair ISO” and wait 1–2 minutes for the process to complete. Once the repair is complete, double-click the new ISO file to mount it, then run the software from the mounted drive.

Choose "Keep personal files and apps" and follow the on-screen prompts to finish the installation.

This method is a reliable windows 11 upgrade tool that skips the need for USB media, but it cannot be used to upgrade to Windows 11 without patching the ISO, so it is only suitable for users who are comfortable modifying system files.

If you don’t want to use a USB drive, you can try this method. It bypasses official hardware requirements, so you should understand the potential compatibility risks before proceeding.