.NET Framework 4 and .NET MVC 3 are baseline requirements. The former is not usually installed by default on a new environment, and the latter almost definitely not.
Use Microsoft Web Platform Installer if possible. Otherwise:
Installers may be available in \\van-fs4\Multimedia\_Software\DotNet
Just installing the appropriate platforms should be sufficient.
TODO: There is a failure case where, depending on server history, installing MVC framework would cause IIS to load DLL versions (32- vs 64-bit). Can be fixed by being explicit about which one to load. Unsure about how—or even if it's possble—to fix the "symlink".
IIS6 relies on file extensions to determine which handler to use. This does not work with MVC's extensionless URLs.
This is worked around by manually defining the MVC handler as a default handler, and turning off "Verify that file exists."