If you have an application that worked great in Windows XP but doesn’t work in Windows 7, give it a try in Windows XP Mode.

Windows XP Mode is an optional download for the Professional, Enterprise, and Ultimate editions of Windows 7. It provides a licensed copy of Windows XP with Service Pack 3, saved in Virtual Machine Hard Drive Image (.vhd) format. When run in Windows Virtual PC, or another compatible program, this virtualized installation of Windows XP lets you run applications that might not run well in Windows 7. Windows XP Mode is also handy if you have an older device with a proprietary driver that hasn’t been updated for Windows Vista or Windows 7. If it worked great in Windows XP but doesn’t work in Windows 7, give it a try in Windows XP Mode.

http://technet.microsoft.com/en-us/magazine/ee851564.aspx