Nothing. The file usually downloads without a file extension, and sometimes
with an unknown file extension. The file should be named x12-30196. You can
try adding the ".exe' extension, but you may not have any better luck than
I've had in my eleven attempts.
Don't bother clicking the second button on the page. It's for a completely
different product - a new Accounting software package. Ironically, that
installs ok.