Windows 10: Dual boot Windows 10 32 bit and Windows 10 64 bit

Hi

I have win10 64 installed on my SSD and win10 32 bit on a HD. The SSD is GPT partitioned and the HD MBR. I can boot from the Windows boot loader in the BIOS into 64 bit windows on the SSD and, by selecting the appropriate HD in the BIOS into the 32 bit windows in the HD. I cannot figure out how to get that boot menu (either gui of text based) that I have read about in the forums. Do I need to convert the HD to GPT as well. Do I need to change anything to get this to work?

Thanks for any advice and ask if you need clarification.

:)

 

Dual Boot Windows 10

I am Currently Running Windows 10 64 Bit. I would Like to Add Windows 10 32 Bit as a Dual Boot.

I have older games that will play on 32 Bit But Refuse to Play On 64 Bit of the windows 10 OS.

Will this cause confusion on Dual Boot as it is the same OS bit Different Bit#s?

 

The parameter is incorrect. How to fix?

28 GBs is severely limited for setup a dual boot between Windows 10 32 and 64 bit.

You need to install a larger hard disk or SSD.

You are not gonna get far.

What is the objective of wanting to dual boot 32 and 64 bit Windows 10 by the way?

 

The only restriction that I know of is that you have to boot from the GTP disk. From an elevated command prompt on your GTP disk. type bcdboot D:\Windows where D is the drive letter of the HD disk. You will want to use bededit to change the descriptions in the boot menu since both will be windows 10 otherwise. This is from the tutorial forum. Operating System Name at Startup - Change in Windows 10 - Windows 10 Forums .

 

Thanks JohnC. I was away yesterday so have yet to try this later today. But it looks like I will be fine. Another thing, I noticed that although my BIOS mode was UEFI when I started this, since I added the new MBR HD drive and OS, the mode has changed to LEGACY. Will it change back if I convert the HD to GPT? If not, how do I get my BIOS mode to revert to UEFI? Maybe an inplace upgrade?

I will post my results later on today.

Thanks JohnC.

 

I did as you suggested. Booted into the GPT drive and added boot files to Windows Boot Manager and changed the names. So far so good. But when I rebooted the computer, the BIOS entry UEFI Windows Boot Manager which I previously used to boot into to start 64 bit windows is no longer there. I can see the GPT drive in the BIOS status screen and if I select it to boot, I cannot boot from it. I can only boot into the mbr HD drive. Obviously something is not right but I cannot figure this out.

Entering bcdedit on the HD drive shows a windows boot manager section and a windows boot loader section pointing to the C; partition, which is the right partition that I am booted into. The other partition shows up as d:.

Please ask for clarification if necessary but right now I can only boot into the mbr HD drive.

As it stands I am stuck in the 32 bit windows with no way of accessing my 64 bit.

Thanks.

 

To copy boot files for both EFI and MBR to the bootloader, specify the /f ALL parameter.
eg: bcdboot C:\Windows /s C: /f ALL

 

One question, Superfly.

Given my situation that I cannot boot into the GPT drive, do I enter this command in an elevated command prompt in my mbr HD drive?

My system drive is c: and the other drive is d:. Please excuse me but I don't want to make another mistake and make matters worse!

 

The MBR Boot folder has both types of boot files - so it doesn't matter...

 

I tried this and I get an error saying could not open the BCD template store. Status [c000000f] What is wrong?

 

Seems BCD is corrupt try this:

attrib c:\boot\bcd -h -r -s
del c:\boot\bcd
bootrec /rebuildbcd

Then run bcdboot again.

PS: If all else fails, you have a 64 bit UEFI (hopefully it is 32 bit) that can't boot from the 32 bit boot files - in which case these commands can be run from the 64 bit install media recovery options.

 

Sorry, I guess I mistyped previously. So I entered the command exactly as indicated. This time the command executed successfully but I still can only boot into my mbr HD by selecting the drive at BIOS. If I select my SSD in BIOS, the computer does not boot. Also, Windows Boot Manager does not appear as an option in the BIOS, which I think it should, no?

 

OK, I tried something else and I think I have fixed this. Using EasyBCD info from this forum, I noticed that there was only one entry in the BCD so I added one for the 64 bit windows and I now can boot from either. IN the process I have learned a lot about this (thanks JohnC and Superfly). I will mark this as solved