Hello all, I figured I'd share a fix I found after spending a couple days trying to get sound working in Windows 98 for my Yamaha YMF724F-V.

Symptom: Immediately after install of the Yamaha DS-XG v4.07.1040 driver for Windows 98, my PC would freeze. On reboot, it would freeze a few seconds after the splash screen. In safe mode, I could run the Uninstaller and remove the drivers to restore it - simply disabling the drivers and rebooting did not work.

Cause (?): The installer installs three drivers, even if you use the extracted version and only tell it to install one single driver for the "PCI Multimedia Audio Device":
- YAMAHA DS-XG GamePort
- YAMAHA DS-XG Legacy Sound System
- YAMAHA DS-XG PCI Audio CODEC

I had disabled Game Port in my BIOS to be sure it wouldn't conflict if they were competing for the same resources.

Fix: After tons of messing around with different drivers, I came across an easy fix.

1. Download the extracted version of the driver (where you can see folders RealDOS, WIN9X, WinNT, etc).
2. Boot up your PC and let it prompt you for a driver for "PCI Multimedia Audio Device". Point it to the WIN9X folder.
3. It will install the first driver, "YAMAHA DS-XG PCI Audio CODEC" and have a success message. Normally, you'd click OK and it would install the second and third drivers - but at this point, restart your PC instead!
4. Windows will boot up, complain that it needs a CD inserted to find MMDEVLDR.VXD. Click OK and cancel out of it, and it will continue to your desktop and should have sound.
5. If you look in Device Manager, you will see that the CODEC and Game Port drivers both installed, but the Legacy Sound System driver has a red X and says it can't find a file. Double click the Legacy Sound System entry and check the "Disable in this hardware profile" checkbox and click OK. Optionally, do this with the Game Port device if you don't need it.

That's it! There's probably a more graceful way - such as deleting the bad file out of the installer files or out of the installed drivers from Safe Mode, but this is good enough for me and might help someone in a pinch.