Hi,
You see in the footer of the error its using .NET 1.1 framework. You need to install .NET 3.5 SP1 (if its not already installed) and in IIS you should be able to choose 2.0 .NET (3.5 is really a superset of 2.0 so you won't see an option for 3.5 in the IIS settings).
Hope it helps,
Joe