Windows 11 is currently operating on 78.8% of Windows devices, while Windows 10 holds a 16.9% share. Microsoft ceased support for Windows 10 on October 14, 2025, making it vulnerable to security threats. Eligible Windows 10 devices can receive Extended Security Updates (ESU) until October 12, 2027, through a paid program, with free ESU available for users in the European Economic Area until October 14, 2026. Approximately 21.4% of devices in small and medium-sized businesses and 16.6% in large organizations still run Windows 10, often due to budget constraints. Devices in industries like healthcare and manufacturing are particularly slow to adopt Windows 11. Windows 10 devices face nearly three times the number of active vulnerabilities compared to Windows 11, with 66.6% rated as high or critical. About 2.8% of Windows 10 systems do not meet the hardware requirements for Windows 11. A total of 18.7% of Windows devices are running unsupported operating systems, with 22.2% on versions that will reach end of support within six months, totaling 40.9% of systems that are unsupported or soon to be. The consumer ESU program will expire on October 12, 2027, after which many devices will transition to unsupported status.