If you are willing to debug a bit, try this:
Open a command prompt (in the search bar in the bottom left of Windows, search for cmd.exe)
So once the command prompt is showing (it's a mostly-black terminal where you can type into), paste this:
msiexec /i "%USERPROFILE%\Downloads\JamKazam-1.0.3928.msi" /L*V "out.log"
The thing I'm assuming here is that your downloading JamKazam.msi file is in your Downloads directory. It probably is, but not always if you've configured things in a non-default way in Windows.
If the command above is successful, the installer will open up like normal. Click next-next-next until it fails, as you normally would.
After it's done, back in the command prompt, type this:
start .
This will open up Windows Explorer in the same directory as 'out.log'; so it should be easy now to attach to an email by dragging to gmail or whatever your email app/provider is. If you can send that to support@jamkazam.com, we'll take a look! Hopefully an error is in there!
Please make the subject line MSI Log From Forums.
Seth