The Microsoft Application Compatibility Toolkit (ACT) 5.0 helps customers understand their application compatibility situation by identifying which applications are compatible with the Microsoft® Windows Vista® operating system and which require further testing. ACT helps customers lower their costs for application compatibility testing, prioritize their applications, and deploy Windows Vista more quickly.
You can use the ACT features to:
Verify an application’s compatibility with a new version of the Windows operating system, or a Windows Update, including determining your risk assessment.
Become involved in the ACT Community, including sharing your risk assessment with other ACT users.
Test your Web applications and Web sites for compatibility with new releases and security updates to the Windows® Internet Explorer® Internet browser.
Download Microsoft Application Compatibility Toolkit from here