Microsoft revealed that one billion PCs are still operating on Windows 10, with 500 million being older models ineligible for upgrades and another 500 million capable of upgrading to Windows 11 but opting not to. Microsoft will provide free security updates for Windows 10 home users until October 2026, raising concerns about the vulnerability of many aging systems. There is a potential crisis looming with 500 million outdated PCs, which may lead to environmental issues, prompting suggestions for users to consider alternatives like Linux or ChromeOS.