Installing .NET 4.0 on Windows Server 2003 SP2

I live in the world of Dark Matter developers where we still have to support mission-critical applications running on Windows Server 2003, SP2, 32 bit. At least I have the ability to upgrade to .net 4.0 on this machine. However, when I run the .net 4.0 full installer, I get the error:

Final Result: Installation failed with error code: (0x800B0100), "No signature was present in the subject."

Does anyone know how to get this to work? I have done it on a similar machine, but that was about a year ago.

Ok, I got it. I had a bad installer, a lightweight one that needed to download components. When I got the right full package, and ran as Admin, then it installed just fine. The machine I was on did not allow downloads from Microsoft.

Here's the package I used:

http://www.microsoft.com/en-us/download/details.aspx?id=17718