The Microsoft Application Compatibility Toolkit (ACT) 5.5 helps customers understand their application compatibility situation by identifying which applications are compatible with the Windows 7 RC and 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 more quickly.  

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=24da89e9-b581-47b0-b45e-492dd6da2971

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.

  • Supported Operating Systems: Windows 2000 Service Pack 4; Windows 7; Windows Server 2003 Service Pack 1; Windows Vista; Windows XP Service Pack 3
  • Supported Database Components: Microsoft® SQL Server 2005, Microsoft® SQL Server 2005 Express Edition
  • Miscellaneous Software Requirements: Microsoft® .NET Framework, version 2.0

Additional resources for Application Compatibility

Application Quality Cookbook for Windows 7

ACT 5 Step by Step Guides