If you have not (still) upgraded to Windows 10 from, for example, Windows 8 or Windows 7, then you are officially too late. Microsoft's free upgrade offer has now expired. But the upgrade tool is still available for download. For now, at least. You can still update to Windows 10 for free.
As of January 14, Microsoft will stop supporting Windows 7. No updates or other support to protect your PC will be released for this operating system. Fortunately, there has been a way to switch to Windows 10 for free for years.
Back in 2015, Microsoft already offered the option to upgrade from Windows 7 and Windows 8 to Windows 10 for free. That upgrade offer is officially over, but Microsoft has another upgrade option for you.
Microsoft has been offering a free upgrade for users who work with so-called assistive technologies since 2016. Assistive technologies are nothing more than programs that help the less able to use the computer. Think of the On-Screen Keyboard or Narrator. The difference with this upgrade method and the previous one is that you can only install it directly over an existing Windows 7 installation, and cannot run it as a clean version. Incidentally, the tool did not check whether you actually used supporting software.
Download tool via direct link
To perform the upgrade, you had to go to the special Microsoft website and you could use the tool Windows10Upgrade24074.exe to download. The download button has now been removed, but the executable itself can still be downloaded. The file Windows10Upgrade24074.exe can still be downloaded via this direct link. (https://download.microsoft.com/download/0/1/6/01677C03-1D89-49FD-B49B-87B0F36B00D1/Windows10Upgrade24074.exe).
Don't want to upgrade yet? Then you save the file in a separate place, for example on a USB stick, so that you can still perform the upgrade later. It is not known whether the tool also checks whether you are eligible for the free upgrade.
Are you still using Windows 8.1? Even then, it is wise to upgrade to Windows 10. Microsoft has stopped the basic support of Windows 8.1, so that only patches are now released, but no new functions.
Many new features have been added to Windows 10 over the years, making it worth upgrading from Windows 7 or Windows 8.1.