Booting NVMe in Bios Legacy HW.... all OS.

By juanpc2018 at 2021-08-15 • 0 collector • 24 pageviews

found something amazing....

its called DUET Bootloader... a fork of Clover + rEFInd

allows to Boot UEFI OS, in Old Bios Hardware.

having all the advantages of UEFI,

over 4TB hdd, NVMe boot, GPT, etc...


Windows8.1x64 has NVMe drivers, R&W NVMe, But...

Old Bios cannot Boot NVMe, Nor GPT.

DUET Bootloader allows to break the 600MB/s SATA-III barrier in old Bios boards,

with M.2 to PCIe_x4 adapter like:

having 1500MB/s R&W in Old Boards with PCIe v2.0

or 2500MB/s with special M.2 to PCIe adapter that use all x16 channels in PCIe v2.0

like Sonnet 4x4 M.2

HighPoint 8xM.2 has x16 PCIe but i dont know if joins all x16 channels when used as PCIe v2.0

speed depends on available CPU lanes, having other cards eats lanes.

Old = year 2010, x58 intel chipset, Nehalem & Westemere CPUs socket 1366,

AMD Opteron 6*00 series CPUs G34 socket.

Server Boards AMD & Intel from Tyan and Supermicro

and similar PCs with PCIe v2.0 SATA 3Gbps 6Gbps, DDR3 memory..

as far is i know and tested, No Old board can boot UEFI partition, or GPT, or NVMe.

DUAL USB allows to boot UEFI in Old Non UEFI Boards.


MBR + UEFI works Ok.

No need to convert to GPT if booting on a PC.

on MacPro5,1 2010 "has UEFI" and creates a conflic,

having dual Bootloadres with MBR.

to Boot UEFI... requires to change the bootloader,

when Win8.1x64 is installed on a Bios machine or Legacy mode in a new machine, installer creates a Bios bootloader, that needs to be erased, to create a New Windows bootloader with UEFI or UEFI+Bios.

Oversimplified Steps:

create a Windows Recovery USB drive,

boot from recovery USB.


select boot partition, Not the c:\Windows drive.

delete boot partition,

Do Not type Clean,

Clean Erase the whole HDD/SSD..

Do Not type Clean.

format boot partition as fat32,

exit diskpart

bcdboot /f ALL to install Bios & UEFI bootloader, or UEFI or Bios, to create a only UEFI or only Bios boot partition.


reboot from DUET USB

msinfo32.exe in cmd / terminal, allows to see if Bios Mode: Legacy or UEFI.

there are many Online video tutoriasl:

when Windows boots Ok from UEFI, 1st time takes time coming from Bios Legacy boot.

then move Windows to a New NVMe drive...

creating a Restore Drive to an external 1TB USB3.0 drive..

turn off, remove the source HDD/SSD,

Boot Duet

Boot Windows Recovery USB

"2x different USB sticks",

Windows Recovery USB, can only restore a Bios Windows in a Bios machine,

and UEFI Windows in a UEFI machine.

Does Not allow to boot Bios, and restore UEFI Windows.

Does Not allow to boot UEFI, and restore Bios Windows.

Restore Windows from 1tb external Drive to New NVMe drive.

Turn Off,

remove Windows USB,

Reboot DUET,   Boot from NVMe.

Activate Windows again,

if its a Retail Version allows unlimited activations.

OEM Windows Only allows 1 Activation, to avoid people stealing windows in large companies.

there are other paid options using: EaseUS Partition Master.

P.D. DUET2020 USB creator does Not create USB in Win8.1,

everything works exept creating a modified MBR Boot USB,

requires W10x64 to create the modified MBR Boot USB.

but then Duet USB works OK with Win8.1x64,

only has problems creating the USB. then works ok.

W10 can be a VirtualMachine like: Orable VirtualBox, VMWare, Parallels, etc...

USB should work ok.

IF want to convert MBR to GPT:

needs to install the MBR2GPT tool + the other steps.


but if you create a Windows Restore drive, BEFORE

there is No risk.

insert NTFS 1TB drive,

Control Panel / System & Security / File Hystory.

Create USB

Create Backup


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