You need to update.

After installing Windows, not all Windows and programs are updated. If your version of Windows OS was released before 2015, you will have the same version. Even if you do not want to update your Windows OS, you do need to update your Defender, program software, and drivers. Drivers are updated and some programs may not work if the OS is not updated. Therefore, it is better to have everything updated to work with the compatible Windows OS and drivers.