Can't setup share RAM to VGA on BIOS !

My computer running with Windows 7 Pro. Because setting RAM Shared to VGA onboard large ( 850MB per 2GB RAM ); alway, i check my graphic memory used and never use over 100MB.
I find many tutorials How to downgrade RAM share to VGA- one way to config in BIOS. But with Menu setting of mainboard G41MD, I can't find it in Advanced setting ( and other setting in BIOS ).

Help me, I will down RAM share VGA to max 256MB.
My hardware info in report.rar attach file

Any body care?
I create file export.rar by Aida64, direct upload to forum !

At the moment you only have 128 MB of system memory allocated for video. From your report,

Integrated Graphics Controller:

Graphics Controller Type Intel GMA X4500
Graphics Controller Status Enabled
Graphics Frame Buffer Size 128 MB

What you are referring to is something that you cannot change. This is what you are referring to,

Video Memory Virtualization - A Brief Guide

which is totally dependent on the amount of system and video memory, and cannot be changed unless you want to try hacking the Windows kernel.