Bios Mods -The Best BIOS Update and Modification Source

Sorry for the long winded post but ...

I was wondering if someone could help with a BIOS mod for Dell Insprion 20 3043 All In One Desktop. It came with Windows 8.1 and I want to install windows 7 on it, I know windows 10 is out but I would prefer windows 7. The thing is, if you do a quick search on installing windows 7 on this Dell Insprion 20 3043 it comes up with alot of people who have had issues & it seems impossible to do. Every time you try to install windows 7 on this computer it gives you a BSOD screen saying "BIOS in this system is fully ACPI compliant" and an 0x000000A5 stop error code.


A brief history of the BIOS for the Dell Insprion 20 3043 and issues ....

BIOS A03 (original release) - A07 (Jun 9 2014 - Dec 19 2014 release dates)
you could disable Secure boot but it will NOT allow you to choose the Boot List Option to change it from UEFI to Legacy. That menu option in the BIOS is greyed out.

BIOS A09 - A12 (last BIOS release) (Apr 13 2015 - Nov 26 2015)
Now when you turn off 'Secure Boot' the 'Load Legacy Option Rom' setting became available and once Legacy Option Roms are enabled, you now have options that became available in the one-time-boot menu (USB option won't show up till you plug in a USB drive). So now you can boot from a legacy CD rom or USB stick and try and install windows 7 but when you try to you get a BSOD saying ...

The BIOS in this system is fully ACPI compliant". Please contact your system vendor for an updated BIOS"
Technical Information:
*** stop 0x000000A5 (some other 0x0000 codes)


[attachment=12296]


The thing is I'm on the latest BIOS revision (A12) and it still won't install windows 7 on this Dell Insprion 20 3043.

Info on the computer below.

Manufacturer: Dell
-Model: Inspiron 20 3043 All In One Desktop
-Bios Revision: A12
-Bios Release: 26 Nov 2015
-Bios link: https://downloads.dell.com/FOLDER0338782...43_A12.exe
-Bios Type: Insyde


Can anyone help or is this a lost cause??

PS just to see what would happen, I was able to install windows 10 on it with no problems, but again I would like to have windows 7 if it is possible.

Thanks,
PD

I tried doing what BDMASTER suggested in another thread and tried to use Hiren's Boot DVD and even tried wondershare live boot and it gave me the same BSOD stop error "The BIOS in this system is fully ACPI compliant". Please contact your system vendor for an updated BIOS"
Technical Information:
*** stop 0x000000A5 (some other 0x0000 codes)"

[attachment=12306]



I even tried to sysprep but it is stuck in a loop. It will try and start windows 7 but hangs at starting windows

[attachment=12304]

and then send me in a loop back to windows error recovery and want me to select an option between safe mode, last know good, start normally.

[attachment=12305]


I tried all options but the same loop happens.

I tried doing all kinds of combinations but still haven't been able to get windows 7 installed on this dell 3043.