This sound card came from the factory with 2 different chipsets AD1848 and CS4231. If your card has the AD1848 codec then use the file azt16a95.zip.
If your card has the CS4231 codec then use file azt16b95.zip.
Although these were written for Windows 95 they should work equally well in Windows 98.
Unzip to a temp folder/drive and decide which file you need before applying. There is a screen shot of the website explaining the differences in the 2 versions (htm file).