Are you using moded drivers for GTX 970 ?
Is "Nvidia HD Audio" device present and it's driver installed ?

Yes , I am using this modded driver I found at this website: https://www.philscomputerlab.com/modified-nvi … ia-drivers.html

Nvidia HD Audio is shown Device Manager.

I ended up using my portable speaker connected ro my old soundcard via aux, since since the windows xp wasn't compitable to my hifi system trough displayport.

Audio over HDMI or DP doesn't work correctly in XP, IIRC ATI works better for this than nVidia and yes its driver related and XP in general not liking sound over HDMI or DP.

I remember back in the day always having issues with it, personally I just disable it and a use SPDIF connection to external sound systems.

Even on my modern systems I refuse to use sound over HDMI or DP .. its always been terrible and I go so far as to remove that component from the drivers to stop windows defaulting to it on every damn driver update.

Trashbytes wrote on 2025-03-03, 23:22:

Audio over HDMI or DP doesn't work correctly in XP, IIRC ATI works better for this than nVidia and yes its driver related and XP in general not liking sound over HDMI or DP.

I've gotten it working on a laptop with the Intel GMA 4500MHD chipset. All I had to do was install the graphics driver.