Yes, you need the .NET framework for the launcher to work. Get it here.
Don't worry, I've already solved the problem, installing the Microsoft .NET Framework sequentially by their respective versions, starting with the 1.0 - 1.1 - 2.0 - 3.0 and finally the 3.5, all this after use the CleanUp Tool to remove remaining data in registry. But thanks for suggest another solutions.