Does your soundcard work with any other
program? I had a similar problem and the popping noise was
caused by an irq conflict between my soundcard and the
parallel port. Changing the irq from 7 to 5 fixed it in
that case.
If your soundcard works, are you sure you installed the
MS-Agent software correctly? The article says some people
had problems until they installed the entire package.
Last (but not least) is the code you're trying to run. We
can't do much to help until we see what you're trying to
run. Post a snippet here if you could, please.