Hi

I have DELL Vostro 3500 laptop with switchable graphics. Some vendors from that time gave an option in BIOS to disable this feature and select only one active graphics card. Unfortunetly DELL isn't one of those vendors and I'm forced to use outdated DELL drivers for switchable GF310M. I would like to update AHCI part, because the chipset is P55, but it uses Intel 8.9 AHCI BIOS.

BIOS can be downloaded from here: ftp://ftp.dell.com/bios/3500_A10.EXE
I have extraced ROM and HDR file with /writeromfile /writehdrfile switch - my fist question - what's the difference?
I have used AMITOOL to replace AHCI BIOS with newer 12.7 in the ROM file.
I have used AMI BCP 4.53 tool to enable some hidden options in bios - all settings are marked show - yes, so I only changed Access to USER for settings I want to see.
Now the fun part.
I used AFUWIN for Aptio v 3.05.02 to flash this modified BIOS ROM file.
This tool won't allow me to flash HDR file, saying the size is different.
It allowed me to flash my modified ROM file only when I checked "Do not chceck ROM ID", I flashed only Main BIOS Image - not boot, nvram, me etc.
But, there are no new options in BIOS. I'm afraid to try again, this time flashing everything, because I'm afraid I will brick my laptop. Also, ROM file is 4MB in size. HDR file is around 2.6MB and I did a backup of oryginal BIOS with AFUWIN, it's also 2.6MB in size.

Can someone help me - how to enable those hidden options? How to flash this weird DELL BIOS and not brick my laptop? What is ROM and HDR file for? Is there a way to unpack EXE file, because I can't find any temp folder, which this DELL exe extracts to? Why is ROM ID different when I use /writeromfile from oryginal BIOS exe file - Winery01 and Winery13? ROM GUID is the same.

Regards