The provided information highlights that as of the date near Windows 10's end-of-life (EOL) in 2025, approximately 40% of corporate client devices continue to run Windows 10. Microsoft has announced that mainstream support and security updates for Windows 10 will cease after this EOL date, meaning that devices running this OS will no longer receive security patches or updates. This situation creates a significant security risk because any newly discovered vulnerabilities in Windows 10 will remain unpatched, leaving systems exposed to exploitation. Attackers often target unsupported operating systems due to their unpatched vulnerabilities, which can lead to unauthorized access, data breaches, ransomware infections, and disruption of business operations. The threat is exacerbated in corporate environments where Windows 10 is widely deployed, and legacy applications or hardware dependencies may delay migration to newer supported OS versions such as Windows 11. The lack of ongoing security updates increases the attack surface and potential for exploitation, especially as threat actors develop exploits targeting known but unpatched vulnerabilities. The information does not specify particular vulnerabilities or exploits but underscores the systemic risk posed by continued use of an unsupported OS in corporate environments.

For European organizations, the continued use of Windows 10 post-EOL presents a heightened risk of cyberattacks that could compromise confidentiality, integrity, and availability of corporate data and systems. Sensitive personal data protected under GDPR could be exposed in breaches, leading to regulatory penalties and reputational damage. Critical sectors such as finance, healthcare, manufacturing, and government agencies are particularly vulnerable due to their reliance on Windows-based infrastructure and the high value of their data. The lack of security patches increases susceptibility to ransomware, malware, and advanced persistent threats (APTs), potentially causing operational disruptions and financial losses. Additionally, supply chain risks may arise if third-party vendors or partners also run unsupported Windows 10 systems. The impact is compounded by the interconnected nature of European business ecosystems and the strategic importance of maintaining robust cybersecurity postures to comply with regulatory frameworks and protect critical infrastructure.

European organizations should prioritize a comprehensive migration strategy to supported operating systems, such as Windows 11 or Windows 10 Enterprise LTSC versions with extended support where applicable. This includes conducting thorough asset inventories to identify all Windows 10 devices, assessing application compatibility, and planning phased upgrades to minimize operational disruption. Where immediate migration is not feasible, organizations should implement compensating controls such as network segmentation to isolate legacy systems, enhanced endpoint detection and response (EDR) solutions, strict access controls, and continuous monitoring for anomalous activities. Regular vulnerability scanning and penetration testing should be conducted to identify and remediate exploitable weaknesses. Organizations should also ensure robust backup and recovery procedures are in place to mitigate ransomware risks. Employee awareness training on phishing and social engineering attacks remains critical. Engaging with vendors for extended security updates or support agreements may provide temporary relief but should not replace migration efforts. Finally, organizations should maintain compliance with GDPR and other relevant regulations by documenting risk assessments and mitigation actions related to legacy OS usage.