A military AI computer network created by Cyberdyne Systems that gains sentience and begins a genocidal war against humanity when US military officials try to pull the plug on the project. Sends two Terminators back in time, one to destroy opposition leader John Connor's mother before Connor is born, and one to eliminate Connor ten years later.
Skynet's undoing was its use of humans to dispose of bodies in its death camps.
The Terminator movies warned of the apocalyptic end of humanity if Skynet is not shut down permanently.
With the numerous security flaws in Microsoft's products, a hacker can easily create bugs which will guide Microsoft Windows into becoming a self-aware, Skynet-like system.