Yamaha Softsynths doesn't work in Windows 7 unlike Windows XP. However, there is another way to play XG MIDI files on Windows 7.
Yamaha MidRadio won't install properly on Windows 7 but setting the compatibility settings to Windows XP for the setup and executables, it will run and play the files.
On the downside, the interface is written in Japanese so you will have to guess which is which.
