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To provide a more secure experience, beginning with Windows 11, version 24H2, JScript9Legacy is enabled by default to handle all scripting processes and operations that previously used JScript. Read on to learn more about frequently asked questions for switching from Jscript to JScriptLegacy and its default in Windows 11, version 24H2.

How is JScript9Legacy better than JScript?

Based on JScript9, the new JScriptLegacy scripting engine offers improved performance and security features. JScript9Legacy is designed to be more compatible with modern web standards, which helps mitigate the risk of cross-site scripting (XSS) and other web-based attacks. The new engine incorporates advanced security features such as improved handling of JavaScript objects and stricter execution policies, which make it harder for malicious scripts to exploit the system. By replacing JScript.dll with JScript9Legacy.dll, the operating system can better defend against a wider range of security threats, ultimately providing a more secure environment for users.

What’s the impact of this change on other in-market versions of Windows?

There is no impact on Windows versions earlier than 24H2. This change is limited to Windows 11, version 24H2 and above. All scripting processes that rely on JScript in Windows versions earlier than Windows 11, version 24H2 will continue to run as they have.

Are there any additional steps needed to take advantage of JScript9Legacy?

No additional action is required from you to benefit from JScript9Legacy, nor will it impact existing workflows.

If there are incompatibility issues with JScript9Legacy, how does one roll back to JScript?

Please connect with our support team through Services Hub for guidance on rolling back to JScript.

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