It isn't a Win 7 issue. I have Win 7 Pro 64bit and my sounds work.

I did this so you can try this as a way of getting the sound to work.

Go to the FSX\Captain_Sim\727 folder and open the sound.ini file. It should open with notepad. Find the following line:

SoundOffWhenSimIsSlew=1

and change it to:

SoundOffWhenSimIsSlew=0

Then you should hear the sounds. You will still have to reload the 727 for them to work though as that seems to be a new problem with v2.4.

Mark