Application Compatibility Toolkit 5.0 Release Candidate Now Available for Download
The Application Compatibility Toolkit 5.0 Release Candidate can be used on XPSP2 with IE7 to help you find compatibility issues:
http://connect.microsoft.com/Downloads/DownloadDetails.aspx?SiteID=81&DownloadID=4028
Note you will need SQL Server 2005 Express Edition SP1 and .NET Framework (1.1 and later)
Product guide:
http://connect.microsoft.com/Downloads/DownloadDetails.aspx?SiteID=81&DownloadID=1570
Release notes:
http://connect.microsoft.com/downloads/downloadDetails.aspx?siteid=81&downloadid=1654
And, let's not forget the Internet Explorer Readiness Toolkit:
http://www.microsoft.com/downloads/details.aspx?familyid=D13EE10D-2718-47F1-AA86-1E32D526383D&displaylang=en