What should I do when the VAIO using YAMAHA DS-XG PCI Audio CODEC does not produce sound?

What should I do when the VAIO using YAMAHA DS-XG PCI Audio CODEC does not produce sound?
or
Why can't I install a driver normally when I remove [YAMAHA DS-XG Driver (or WDW)] using [Add/Remove Programs]?
or
When I remove [YAMAHA DS-XG Driver] and re-start the system, [PCI Multimedia Audio Device] is detected with Plug & Play and the [Add New Hardware Wizard] window appears. Even though I specify "C:\WINDOWS\INF" or "C:\WINDOWS\OPTIONS\CABS" as the browsing source of the driver, the driver cannot be detected and is recognized as [Other Devices] as a result. Why is that so?

The machine cannot produce sound as the sound driver has been removed. However, resetting the sound driver from the Recovery CD-ROM will enable the sound driver to be installed to the machine normally.

To reset the sound driver, please refer to the following procedure:

(Procedure)
1. Insert Recovery CD-ROM Vol. 2 of 2 (*) into the CD-ROM drive.
* Basically, you should insert the last Vol. number of Recovery CD-ROM. The version may vary depending on your computer.

2. Open the CD-ROM drive from [My Computer] and execute [\VAIO\DRIVERS\WIN98\SOUND\SETUP.EXE] to set [YAMAHA DS-XG Driver].

3. Re-start the system as prompted after the setup is completed.

The sound driver, which enables the machine to produce sound, is now installed to [Sound, Video and Game controllers] in [Device Manager] normally.