[Request] Vaio VGN-Z11WN - Unlock dual graphics switch/advanced menu

[gas]

Hail masters,
I've a second hand notebook that is amazing except for the linux compatibility. I would be able to unlock advanced features to modify the switch between Intel and Nvidia video cards in bios settings.

I tried by myself with the following tutorial: http://forum.notebookreview.com/sony/473...-bios.html
But it didn't work out-of-the-box, I tried to modify the VSS offset searching for the Hex sequence 24 56 53 53... but it didn't work either (and I'm not good in this hacks).

- Notebook model: VAIO VNG-Z11WN
- Os: Windows Vista
- Bios version: InsydeH20 Rev. 3.5
- Bios download link: http://www.sony.co.uk/support/en/content.../VGN-Z11WN

Please, help me!

-- Edited
Added BIOS screenshots.
Added BIOS dump obtained with 'flashit.exe' tool.

[gas]

Hello people,
did I forget something in the request?

Is there anybody able to tell me if it is possible to obtain what requested?

Thanks,
Gas