This is a rather odd fault that can occur during the installation of Exchange 2013 (and possibly other versions) if a previous installation failed and had to be cleaned up manually. The full error message is...
The type initializer for 'Microsoft.Exchange.Configuration.Tasks.ThrottlingModule`1' threw an exception.
Microsoft gives no information on what this means and the installer provides nothing more useful. Trying to install via the command line (PowerShell) throws out a myriad of errors, none of which are true, for example that the user running the installer isn't in the correct groups, etc.
To fix this problem, you need to remove the Microsoft Exchange key from the Windows Registry and then add back a few keys in particular.
The key you need to remove is...
And the keys you need to add back in are...
Windows Registry Editor Version 5.00
... alternatively you can save the above block of code as a .reg file and run it which will create the keys for you.
Once you have done this, you should be able to run the installer again successfully. If you get any more issues then run the installer via PowerShell instead which will provide considerably more useful output and seems to sidestep a few nit-picky issues the graphical installer falls over on.