Just run the enclosed .exe (bat file didn't seem to do anything).
The following files are found inside the driver download file.
|Setup.bat||158 bytes||2 Jan 1998|
|mgx401.drv||9.2 KB||16 Jan 1998|
|GXAUDIO.INF||7.9 KB||9 Apr 1998|
|mgxfm.drv||18.6 KB||16 Jan 1998|
|mgxsb16.vxd||23.7 KB||10 Mar 1998|
|Drvins.exe||6.0 KB||29 Sep 1997|
|Setup.PIF||967 bytes||28 Feb 2000|
|MGXSB16W.drv||49.7 KB||16 Jan 1998|