Hello
I have a laptop with one empty drive and like to Dual Boot 32-bit Windows 10 with 8.1 in UEFI mode, is it best to install 8.1 or 10 first ? Also, is it easier to install Windows 8.1 and 10 on separate drives ?
Thanks a lot
It does not matter which order as they use the same bootloader. Order was more important with W7 as it used an older boot loader.
Also, it depends on drive types whether you use separate drives.
If one is an ssd and other hdd, better to install both on ssd.
If both drives are ssds or both hdds, I would
a) Install W10 first on drive 0
b) remove drive 0 temporarily
c) install W8.1 on drive 1
d) replace drive 0
e) boot into drive 0 (setting bios to boot from that drive)
f) note drive letter for 8.1 Windows directory on drive 1(say E)
g) run this from admin command prompt
bcdboot e:\windows /p /d
h) reboot pc and you can now select either OS.
So why do all the above - If you did not remove drive 0, boot files for W10 and W8.1 would reside on drive 0.
The problem with this is if drive 0 fails or gets corrupted, you would not be able to boot into drive 1.
With the above, you can boot either drive independently.
BTW: why use 32bit W10 (legacy bios) and 64bit 8.1 (uefi). On some pcs, you might not be able to dual boot from a menu - some may need you to set bios to legacy bios to boot W10, and uefi to boot W8.1 in UEFI. Some pcs are clever enough to choose automatically.
Surely better to have 64bit uefi on both?
My laptop does not support legacy bios anymore. I can only run 32bit in a virtual machine.
I am assuming your pc can boot as legacy bios and UEFI.
I see it is good to know that W8.1 and W10 use the same bootloader so it does not matter which one is installed first. What is the boot loader that W7 uses then ?
Ok that is fine I can find out the drive type is it using.
Good to note if one is ssd and other hdd, to install both on ssd.
Well, it looks like this tablet can only support one drive, and it is M.2 SATA
That is a bit of an involved ordeal with two drives of same type, ssd or hdd, and glad to know the best way to do that is follow A to H as shown here.
Actually, I need W8.1 32-bit and W10 32-bit both in UEFI if that is possible. So if I were to go about this way will I still need to set BIOS to legacy to boot W10 and uefi to boot into W8.1 then ? Or can I get the dual boot menu if uefi is the mode for the BIOS ? The tablet is a Dell Latitude 7350, is that clever enough to do it automatically ?
This Latitude 7350 only has 4 GB of RAM so 64-bit Windows is not worth it.
Yes, all of my PC's from 2021 and after can only boot in UEFI as well
True, this Latitude 7350 is able to boot in Legacy Mode or UEFI Mode, not sure on CSM though.
What is the best steps to take if want to dual boot W8.1 and W10 on one M.2 SATA that is 512 GB ?
Q1 - W7 uses and older version - I cannot remember number but not really relevant.
Q2 You cannot run 32 bit on UEFI on nearly all pcs - there were a few tablets/laptops with special firmware that could do this but they have all but disappeared now. Having said that, I do not know if the Dell Latitude was one of them.
Q3 You do not need all those steps if putting both on same drive - just create two 256GB partitions (or share in whatever proportion you need), and install W10 to unallocated space in partition 1, and then W8.1 to unallocated space in partition 2. Installer will do the rest.
In fact, you should use 64bit as you will run out of primary partitions otherwise. It is rather a myth that 64 bit is not worth it for 4 GB devices.
Drive has to be gpt formatted as well.
Actually, an even better way is to install W10 on the 512 GB drive, and create an expandable virtual hard drive (vhdx) and install Windows 8.1 to that, and create a boot entry for the vhdx using tool like easybcd. This is far more efficient as vhdx file only takes up space used.
I have 6 OSs on my PC - 5 as vhdx files. With 512GB, you could do two or three easily enough.
Sure and I guess it does not matter in this case as we are dealing with W8.1 and W10 so it will not help.
I see was afraid to hear this but is not a big deal will make do with Legacy BIOS then. Do you know what brand the tablet and laptops were with the special firmware, and what it was called ? I wish could find out if this Dell Latitude 7350 is one of them.
Yes I'm relieved do not need to remove a hard drive and put it back here. I think 100 GB for each Windows installation will be enough for my needs. How to know where the 'unallocated space' will be in partitions 1 and 2 ? So, in this case, the W8.1 installer will setup that blue dual boot menu ?
I thought Legacy BIOS can support up to 4 primary partitions, is that right ? Well, I like to install 64-bit on systems with 5 or more GB of RAM, it just makes sense.
Why, isn't gpt format for UEFI and MBR for BIOS ?
Given this tablet or 2-in-1 only has 4 GB of RAM I'd rather not setup a virtual machine on it as that will be slow. I'm too familiar with VHDx but how is EasyBCD able to boot straight into a VM without a host OS ? Yes I always liked how VM drives only take more space as needed. But not for this Latitude 7350.
You must have much more than 4 GB of RAM on this system to run 5 VHDx's on it.
I think he means boot manager ( BOOTMGFW.EFI ). They are not the same.
A virtual disk IS NOT a virtual machine. It is just a software emulation of a physical drive.
As your pc supports legacy bios and UEFI, it cannot be one if the obsolete 32bit UEFI pcs.
You are overthinking things. Either do 32bit mbr or 64bit uefi.
You can native boot into vhdx files. Look in tutorial section.
win8.1 x86 and win10 x86 support efi boot, but I don't know if your bios supports it.Actually, I need W8.1 32-bit and W10 32-bit both in UEFI if that is possible.
Make life easier and use EasyBCD. There are other GUI BCD editors, but I like this one...
Win 8 UEFI install on a GPT drive. Win 10 32 install on a MBR drive. You can't install both on same drive.
As you have two independent drives, install Win10 32 as legacy on the spare drive.
Set BIOS to boot as UEFI or Legacy.
Remove the Win 8 drive before you install Win 10 or you may have a boot manage in Win 8 drive and Win 10 32 OS on the other.
Once you have each OS in its own drive you set the priority boot drive on BIOS. When you want to boot the other drive you launch the boot menu during POST
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