Taken from sony site
NOTE: The sound driver is located in the G:\Drivers\Opl3sa folder.
1. Click Start, point to Settings, and click Control Panel.
2. In the Control Panel window, double-click the System icon.
3. In the System Properties window, click the Device Manager tab.
4. Double-click the Sound, Video, and Game Controllers icon.
5. Click to select the Yamaha OPL3-SA Sound System icon.
6. Click the Remove button.
7. In the Confirm Device Removal window, click the OK button.
8. In the System Properties window, click the Close button.
9. Insert the System Recovery CD into the CD/DVD drive.
10. On the Desktop, double-click the My Computer icon.
11. In the My Computer window, double-click the (G:\) icon.
12. In the G:\ window, double-click the Drivers folder.
13. In the G:\DRIVERS window, double-click the Opl3sa folder.
14. In the G:\DRIVERS\OPL3SA window, double-click SAUNIST.EXE.
15. In the OPL3SAx Driver uninstall Version 1.00 window, click the Next button.
16. In the Uninstall Driver window, click the Next button.
17. In the Uninstall completed window, click the Finish button.
18. Remove the System Recovery CD from the CD/DVD drive.
19. In the OPL3SA window, click the OK button to restart the computer.
20. In the Update Device Driver Wizard window, insert the System Recovery CD into the CD/DVD drive.
21. Click the Next button.
22. Click the Other Locations... button.
23. In the Select Other Location window, type G:\Drivers\Opl3sa, and click the OK button.
NOTE: If the CD/DVD drive letter is not (G:\), replace the G:\ in the command line with the appropriate drive letter.
24. In the Update Device Driver Wizard window, click the Finish button.
Search this site for OPL3-SAx if you dont have the CDRom