Well! Here is a tool from Microsoft called Windows 7 Upgrade Advisor (beta) that scans your PC system, programs and devices for any compatibility issues.
It will let you know compatibility issues with your programs and devices. When the scan is finished, you will see which upgrade options are available and get guidance on fixing the programs, devices issues before you install Windows 7.
The program requires NET 2.0 Framework or higher if running on Windows XP and supports Windows 7, Windows Vista and Windows XP Service Pack 2. Download Windows 7 Upgrade Advisor (beta)