Boot Windows Vista from Windows 10's Windows Boot Manager in UEFI mode.

[Osman Kovan]

I experimented with various options to boot Windows Vista from Windows 10's Windows Boot Manager in UEFI mode and I done it today .

- On VMware, I created 2 separate partitions (one for 10 and one for Vista) and installed Windows 10 in UEFI mode.

- Then, I set Boot policy to Legacy from Standard to show Windows Boot Manager in text mode.

- Then I installed Windows Vista on the 2nd partition and it gives 0x0000001E error (obviously .).

- When I press F10 while Vista's boot entry is highlighted, I added /DEBUG /DEBUGPORT=COM1 and /BAUDRATE=115200 to boot arguments (or select Debugging Mode from F8 menu,).

- When I did the above things and then pressed ENTER to boot system, somehow, Windows Vista BOOTS with Windows 10's Windows Boot Manager in UEFI mode! It finished SysPrep phase and I'm able to reach desktop.

    - When I remove DEBUGPORT and BAUDRATE, it gives 0x0000001E bugcheck error.

    - Also removing BAUDRATE and then

    L changing DEBUGPORT to USB or,

    L changing DEBUGPORT to 1394 and setting CHANNEL to 1 also causes 0x0000001E bugcheck error.

    - Without DEBUG option, adding /DEBUGPORT=COM1 /BAUDRATE=115200 also boots system.

    - Also, without DEBUG and BAUDRATE option, system boots.

    - So, I think, DEBUGPORT=COM1 to COM4 does all this thing, I guess .

- Then, I tried that thing on a real machine (on my spare laptop, Casper CGA-P847, has text-based Phoenix UEFI BIOS.) and also boots with it!

I will write updates to inform you about all things about that.

UPDATE 1: I don't know if it is caused from debugging parameters or Windows Boot Manager itself, Windows Media Sharing just won't work. It freezes the system instantaneously.

UPDATE 1.1: It looks like debugging parameters causing freeze on system while Windows Media Sharing is open .

UPDATE 1.2: Yup, debugging options definitely cause issues with this. I even tried with Windows Vista's original Windows Boot Manager in UEFI mode on VMware. When I disable Windows Media Player Network Sharing Service, the system will boot even when a device is shared. But when I reboot the system, re-enable Windows Media Player Network Sharing Service and when I click start Windows Media Player Network Sharing Service, the system will instantly freeze.

UPDATE 2: When I debug output in VMware using serial port, I saw repeating output like this:

This pattern repeats over and over again and it's 85 hexadecimal long.

And these repeated dots are 7C hexadecimal long.

Edited February 4 by Osman Kovan

[jaclaz]

Interesting.

There is something preventing me to post some comment.

The disk is anyway MBR, isn't it? (or you have some mod to access GPT in Vista?)

Or installing the Windows 10 first allows to install Vista on GPT? (i seem to remember there were issues in attempting to install Vista "directly" on GPT).

in older XP, setting a BAUDRATE automatically switches DEBUG on:

http://smallvoid.com/article/winnt-boot-ini.html

it is probable that also expliciting DEBUGPORT has the same effect of enabling DEBUG automaticallly.

Cannot say if it applies to the bootmgr version you are using, but have you tried the LOCAL option?

jaclaz

Edited February 3 by jaclaz

[Osman Kovan]

On 2/3/2024 at 6:49 PM, jaclaz said:

Interesting.

There is something preventing me to post some comment.

The disk is anyway MBR, isn't it? (or you have some mod to access GPT in Vista?)

Or installing the Windows 10 first allows to install Vista on GPT? (i seem to remember there were issues in attempting to install Vista "directly" on GPT).

in older XP, setting a BAUDRATE automatically switches DEBUG on:

http://smallvoid.com/article/winnt-boot-ini.html

it is probable that also expliciting DEBUGPORT has the same effect of enabling DEBUG automaticallly.

Cannot say if it applies to the bootmgr version you are using, but have you tried the LOCAL option?

jaclaz

1-It's Windows Vista Ultimate SP2 x64 and it's GPT. Windows Vista doesn't need any mod to boot from GPT (on UEFI and SP1+.).

2-Nope, order isn't important. One time on VMware, the system froze sometime after logged in, but when I tried to reinstall again, it didn't happen again. Sudden anomaly occurred while writing BCD data, I guess . Just be sure to press F10 while Vista's boot entry highlighted and add /DEBUG /DEBUGPORT=COM1 /BAUDRATE=115200 or press F8 and select Debugging Mode.

3-I think this is possible . I didn't tried LOCAL option, but I will try tomorrow . But I have little faith in this as here states LOCAL option only effective Windows 8/Server 2012 and above. But maybe from bootloader side, it may work.

Forgot to write. I tried LOCAL option and it didn't help .

Edited February 4 by Osman Kovan