Microsoft has released updated IE App Compat images
VPC Hard Disk Image for testing websites with different IE versions on Windows XP SP2, Windows XP SP3 and Windows VistaIE App Compat VHD
This download page contains four separate VPC images, depending on what you want to test.
IE6-XPSP3.exe contains a Windows XP SP3 with IE6 VHD file
IE7-XPSP2.exe contains a Windows XP SP2 with IE7 VHD file
IE8B2-XPSP3.exe contains a Windows XP SP3 with IE8 Beta 2 VHD file
IE7-VIS1.exe+IE7-VIS2.rar+IE7-VIS3.rar contain a Vista Image with IE7 VHD file.
Note: For The Vista image, you will need all three files, downloaded and in the same directory, then simply run IE7-VIS1.exe.
This VPC image will expire in April, 2009.