Install .NET Framework 3.5 SP1, then try running the Revo R Windows installer again.
It looks like this kind of error can occur when you have a bad install of a pre-existing version of Microsoft .NET Framework on your machine.
I suggest doing the following in attempting to fix this problem:
1). Uninstall Revolution R Enterprise from the Windows Control Panel(look for the 'Revolution R Enterprise 4.0' icon under the 'Programs and Features Group' and remove it).
2). Look for any preexisting versions of 'Microsoft .NET Framwork' under 'Programs and Features' and uninstall
them as well.
3). After doing this, reinstall 'Revolution R Enterprise 4.0' and try running a quick example from the
'Getting Started Guide'.