I did download the files from the Microsoft site and after having a look at it, I was able to determine that if a property called MM is not set in the command line, then they display the prompt asking you to install via setup.exe.
Hence if you try the following, this MSi install should work:
msiexec /i IP4_1.msi MM=1
I'm not sure what the MM property is used. Having looked at the MSI package, this property is being used only to determine whether you are running setup.exe or not.
Let me know whether this works for you.