According to the system requirements provided by the developers, version 7 is compatible with the following operating systems: Windows XP, Windows Vista 32-bit, Windows 7 64-bit, Windows 7 32-bit.
As you can see, there is no Windows 7, but that doesn't mean it won't work on this operating system. Simply right click the setup package and choose Properties > Compatibility then select Windows 7 from the list and tick the Run as Administrator option as well. This should allow you to run the app on Windows 7. You can also ignore the warnings that appear in case that happens.