Windows 10 & Windows 7 Dual Boot - Can it be done

You are good to go. You have no unallocated space until you delete the first partition which is your EFI system partition. The only concern is when you recreate the EFI System Partition with "create part EFI" in diskpart - you want it to be in the correct empty space, so you want the only empty space on the hard drive to be where the EFI System partition was before you deleted it. In my example, after you recreate the EFI System Partition and then do list part, I suspect your system partition will be partition number 1 and it should have the asterisk next to it. When you recreate the EFI system partition it will automatically get the focus for the next command formatting it.

Obviously, your first bcdboot command will need to have D:\Windows in it instead of my G:\Windows.

I ended up with a nice, pretty graphical boot menu with Windows 10 on top and the default after running the commands in the example.

NavyLCDR said:

You are good to go. You have no unallocated space until you delete the first partition which is your EFI system partition. The only concern is when you recreate the EFI System Partition with "create part EFI" in diskpart - you want it to be in the correct empty space, so you want the only empty space on the hard drive to be where the EFI System partition was before you deleted it. In my example, after you recreate the EFI System Partition and then do list part, I suspect your system partition will be partition number 1 and it should have the asterisk next to it. When you recreate the EFI system partition it will automatically get the focus for the next command formatting it.

Obviously, your first bcdboot command will need to have D:\Windows in it instead of my G:\Windows.

I ended up with a nice, pretty graphical boot menu with Windows 10 on top and the default after running the commands in the example.

I'm back. Concluded, when I was sufficiently awake, that all systems were go. Carried out the instructions and et voilà. I can do a 'cold boot' or a 'warm boot' and I have Windows 10 displaying first and it is the default boot option but the icing on the cake is that I now have GUI so there are two icons.

EasyBCD still only shows the Windows 10 entry when booted from Windows 10.

Thanks yet again.

You're most welcome. It was a great learning experience for myself as well! I'm "retiring" in November this year and would love to get a job in computer repair, if I could make enough money at it to take care of the family.

NavyLCDR said:

You're most welcome. It was a great learning experience for myself as well! I'm "retiring" in November this year and would love to get a job in computer repair, if I could make enough money at it to take care of the family.

Best wishes in whatever you do after you retire from the Navy.

I believe it is time to mark this thread as 'Solved'.

As Arnie said, "I'll be back".

NavyLCDR said:

@Nolly1959,
In an earlier post, I eluded to using DISM to apply the Windows 7 image to a partition. This is how you do that. Create an NTFS partition on the hard drive to hold the Windows 7. You can use any partitioning tool you want to. Make sure the NTFS partition is assigned a drive letter - let's assume it gets F: drive.
...

I've been beating my head against the wall trying to get W10 and W7 to dual boot for some time. I will definitely try this method.

Do you know *why* this works? Is this similar in principle to the other solution I've seen, which is to install Windows 7 to an old-style MBR partition, then take an image of it, then repartition with GPT, then restore the image to the GPT partition? Is Windows 7 somehow unable to "see" the partition properly unless it's already on it (either in the form of the setup image or the final installation)?

NavyLCDR said:

@Nolly1959,

In an earlier post, I eluded to using DISM to apply the Windows 7 image to a partition. This is how you do that. Create an NTFS partition on the hard drive to hold the Windows 7. You can use any partitioning tool you want to. Make sure the NTFS partition is assigned a drive letter - let's assume it gets F: drive.

In Windows 10, mount the Windows 7 ISO file. Let's assume the mounted Windows 7 ISO file gets drive letter G:. You will need to open a Command Prompt (Admin), or I believe a Powershell (Admin) will work too. To see what Windows 7 images are available, you will run the same command I did in post #17 on the mounted Windows 7 ISO file:
dism /get-wiminfo /wimfile:G:\sources\install.wim

The drive letter in red will be to the mounted Windows 7 ISO file.

Now to apply the Windows 7 image to the F: drive partition. The F: drive should be empty before you start. You will run the command:
dism /apply-image /imagefile:G:\sources\install.wim /index:2 /ApplyDir:F:\

G:\ above will be the drive letter to the mounted Windows 7 ISO file
F:\ above will be to the empty NTFS partition you created to hold Windows 7
Index:2, change the index number to the version of the Windows 7 you want obtained from the dism /get-wiminfo command.

After the image is applied, you will need to add it to the boot menu. Do that by running the following command:
bcdboot F:\Windows /d /addlast

The F:\Windows will point to the new Windows folder that is created on the NTFS partition after applying the image to it.
You can adjust the boot menu a little bit by running MSCONFIG and changing the parameters on the boot tab.
Reboot the computer, good luck!

My win 7 sticks at the windows startup screen. Ideas?

95GTSpeedDemon said:

My win 7 sticks at the windows startup screen. Ideas?

Consider if you are running EFI or CSM legacy mode.

Windows 7 is difficult to boot in EFI - you can certainly do it but you'll struggle with sleep, hibernation, changing screen brightness and so on.

Better to boot 7 in CSM and 8 and later EFI.

lx07 said:

Consider if you are running EFI or CSM legacy mode.

Windows 7 is difficult to boot in EFI - you can certainly do it but you'll struggle with sleep, hibernation, changing screen brightness and so on.

Better to boot 7 in CSM and 8 and later EFI.

Yes its on win 10, gpt & uefi. I found out the long hard way this wont work with 7.

95GTSpeedDemon said:

Yes its on win 10, gpt & uefi. I found out the long hard way this wont work with 7.

It works just fine with Windows 7. Windows 7 OS works on a GPT drive, it's just that the Windows 7 installer doesn't like to set up EFI System Partitions. It's extremely easy to add Windows 7 to a Windows 10 bootmenu to set up dual booting in UEFI mode, or to create an EFI System Partition to load Windows 7 if Windows 7 is the only OS.