If you have a computer or laptop with a valid licence for Windows 7, 8, 8.1 or 10, you can install Windows 11 on your device and activate it free of charge with your existing, old licence. Microsoft may change its business practice of accepting such activation at any time. Windows 10 will continue to be supported with security updates until 2025.
Switching to Windows 11 may become more expensive at any time, but not cheaper than today.
Here’s how you need to proceed to enable installation on older devices:
Back up your data and create a list of all existing software licences, especially including your Windows licence.
Download Rufus free of charge from the Internet:
Download the ISO file of Windows 11 free of charge from the Internet (third download from above):
https://www.microsoft.com/en-us/software-download/windows11
Use Rufus to create an installation medium for Windows 11 from the ISO file, selecting that you do not need a hardware compatibility check.
Reinstall Windows 11 on your device, including formatting the hard drive, and activate the operating system with your old Windows licence. Then reinstall your software and restore your data. Done!