The simple answer is that for a Hanning window the amplitude correction is 2 and the energy correction is 1.63. These can be found in the theory documents included with your Test.Lab installation. Look for the Signal Processing document.
Thanks, I found it here:
C:\Program Files (x86)\LMS\LMS Test.Lab 16A\central\Help\Theory Documents in the SpectralProcessing.chm, just like you indicated.