[REQUEST] Enable IGP options AMI Aptio

[Master2]

Hi,
I own a Sony Vaio EC2M1E with a Intel HM55 chipset. I'm looking for a possibility to use the IGP as main graphics card. Sony has apparently disabled all options to use the IGP so I hope someone could take a look on my Aptio BIOS.

Thanks in advance!

P.S. I have already taken a look on it via AMIBCP and found something in North Bridge Configuration regarding IGP. It says "muxed with dGPU" for iGPU Digital Port B,C and D.
Any clue what this means?