DirectSound3d not available on Windows 7, how to use a workaround ?

My new PC (Windows 7 based) is equipped with an onboard 5.1 CH HD Audio (Realtek ALC662 Audio Codec) and a Graphics card GeForce GT740 with integrated Audio HDMI, I connect my PC to a HD Sony TV using the HDMI cable.

It is not possible to activate 2D or 3D hardware sound, it go unchecked if I close and reopen a session.

I've also installed 3D SoundBack but still the problem remains.

Can someone suggest me a solution to activate 2D and 3D hardware sound ?

Thanks in advance.

The Direct Sound interface has been dropped from Windows Vista one. Therefore I doubt it would be possible to enable it, except you have a Creative Soundblaster Audigy or newer with which you can use Creative Alchemy to enable 3D sounds.