The simple truth is not all applications will be compatible with Windows 7. Since Windows Vista, parts of the OS and registry are not longer accessible to applications to modify. There are several methods to mitigate application compatibility issues. One of them is with Windows XP Mode for Windows 7. You must be running Window 7 Professional, Business, or Ultimate editions to be able to utilize Windows XP mode. You will also need to install virtual PC on Windows 7. Below are the links to download your copy of Windows XP Mode and the installation instructions.
Once you have Windows XP Mode installed, install you application in the XP mode and give it a try.
Windows XP Mode download: http://www.microsoft.com/windows/virtual-pc/download.aspx
Installation instructions: http://windows.microsoft.com/en-us/windows7/install-and-use-windows-xp-mode-in-windows-7