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Which version of Windows operating system am I running?
Operating system - Wikipedia
Operating System (OS) Definition & Examples - Lifewire
Operating system (OS) | Definition, Examples, & Concepts
What is an Operating System (OS)? Definition, Types and Examples
What is an Operating System? - How-To Geek
Operating System Tutorial - GeeksforGeeks
What Is an Operating System (OS)? Types, Functions, and More
Computer Basics: Understanding Operating Systems
Fundamentals of Operating Systems | Codecademy