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It is possible to use Windows 10 IoT core as an operating system. This is a very light and limited version of Windows 10. You can download the software here: https://docs.microsoft.com/en-us/windows/iot-core/downloads
If you are going to use the Raspberry Pi on your home network, it is already very secure out of the box. However, it is possible to make the Pi even more secure. Here is everything you need to know: raspberry