Download the latest Realtek AC 97 ALC650 Audio CODECs Driver for Windows NT 4.0.
1. Add some customized settings.
2. Add SPDIF IN pass throuth SPDIF Out item for some of ATI and nVidia chipsets.
3. Fix AC3 SPDIF blue screen issue when SPDIF-out force to 44K.
4. Change DMA Threshold from 06 to 10 to decrease noise for ATI SB400 chipset.
5. Update 3D engine to fix Half Life 2(Game) no sound issue and some noise issues.
Here's other similar drivers that are different versions or releases for different operating systems: