The cheapest way to replace Windows is to use a free operating system such as Linux. Linux is an open-source operating system that is similar to Windows but is free to use. There are many different versions of Linux, so you can find one that fits your needs. Linux is not as user-friendly as Windows, so it may take some time to learn how to use it. However, there are many online tutorials and forums that can help you get started. Additionally, there are many companies that offer support for Linux, so you can get help if needed.

You don't need to replace Windows. You can simply upgrade to a newer version of Windows. Upgrading to a newer version of Windows is much cheaper than replacing Windows altogether. In most cases, you can even upgrade for free. So if you're looking for a cheap way to replace Windows, upgrading is your best option. If you're not sure how to upgrade your version of Windows, or if you're having trouble upgrading, contact Microsoft support for help. They can walk you through the process and help you get everything set up properly.