Need help to PROPERLY install dual boot: Windows 10 & Windows 10

@essenbe and @strick: Perhaps you might remember that you helped me do this once before. I want to keep my current Windows 10 (which is faulty) and do a clean install (as you previously advised). There was something to do with the boot manager that you helped me correct. When I am done with the clean install and have installed all my apps, I want to delete the current installation of Windows 10 and have Disk Management set up properly.Attachment 164348
If anyone else wants to help, go for it. I must get this right.

You have a Unallocated disk space at Disk 0. Why don't you format the Unallocated disk space and use it for to backup your personal files. You sound like you don't want to dual boot so why not delete all partitions except for the partition that contains your personal data.

@Nisko,

The first problem that you face is that you have 4 primary partitions already created on Disk 0. That is the most you can have on an MBR type disk, so you have no spot available to create a new partition for a new Windows installation. You have a couple of options. First - what is on G: drive? It shows it as a 453MB partition with about 16MB in use. Can you delete that partition? You also have what appears to be the standard Windows 10 Recovery partition after your C: drive partition. Since the current Windows 10 install is faulty anyway, you can also delete that one.

This is how I would proceed:
1. Delete the Recovery Partition.
2. Copy whatever is on G: drive to D: drive and delete that partition.
3. You will be left with the System Reserved Partition, the C: drive partition and unallocated space.
4. Within your current Windows 10 running, mount a Windows 10 ISO file, or if you already have the Windows 10 installation flash drive created, insert it with the current Windows 10 running.
5. From either the mounted Windows 10 ISO file, or the USB flash drive, run the setup.exe file under the /Sources folder. Do not run the setup.exe file in the root folder. Go to the Sources folder and run setup.exe there.
6. When you get the option for a custom install, choose the custom install option.
7. On the next screen, highlight the unallocated space left on the disk and click next. What should happen is Windows setup should create a partition for the OS, it should create a new recovery partition, and it should add the new Windows install to the existing System Reserved partition as an additional boot menu entry.

If that doesn't work, I can show you how to create a partition in the unallocated space and do a manual install of Windows 10 to it using the DISM /APPLY-IMAGE command and BCDBOOT.

Hello Navy LCDR! You are one of a number of folks who helped me about a year ago (thanks again). What you see in the DM screenshot is what I was left with when we were through. As I recall, there was an issue with the MBR which you folks helped me fix.

I don't recall what the G: drive was for - but there's nothing in it. I also have two images of both drives (at all times) of my system - so there's no chance of me not being able to recover from a mistake. I have the latest redstone version of Windows 10 on a flash drive.

What is the /Sources folder? The last time I ran this flash drive, I just clicked on setup.exe from within Windows 10 and overwrote my old Windows 10 installation to update it.

NavyLCDR said:

@Nisko,

The first problem that you face is that you have 4 primary partitions already created on Disk 0. That is the most you can have on an MBR type disk, so you have no spot available to create a new partition for a new Windows installation. You have a couple of options. First - what is on G: drive? It shows it as a 453MB partition with about 16MB in use. Can you delete that partition? You also have what appears to be the standard Windows 10 Recovery partition after your C: drive partition. Since the current Windows 10 install is faulty anyway, you can also delete that one.

This is how I would proceed:
1. Delete the Recovery Partition.
2. Copy whatever is on G: drive to D: drive and delete that partition.
3. You will be left with the System Reserved Partition, the C: drive partition and unallocated space.
4. Within your current Windows 10 running, mount a Windows 10 ISO file, or if you already have the Windows 10 installation flash drive created, insert it with the current Windows 10 running.
5. From either the mounted Windows 10 ISO file, or the USB flash drive, run the setup.exe file under the /Sources folder. Do not run the setup.exe file in the root folder. Go to the Sources folder and run setup.exe there.
6. When you get the option for a custom install, choose the custom install option.
7. On the next screen, highlight the unallocated space left on the disk and click next. What should happen is Windows setup should create a partition for the OS, it should create a new recovery partition, and it should add the new Windows install to the existing System Reserved partition as an additional boot menu entry.

If that doesn't work, I can show you how to create a partition in the unallocated space and do a manual install of Windows 10 to it using the DISM /APPLY-IMAGE command and BCDBOOT.

OK, I have left the (what I now call it) the Windows 10 (Legacy) partition, the System Reserved partition (F:) and 417GB Unallocated space. The flash drive with the latest redstone version (FCU) is ready to go. Please explain the /Sources folder and why I should run setup.exe from there. I can learn something from an explanation. BTW, I used Mini-Tool Partition Wizard.

Nisko said:

OK, I have left the (what I now call it) the Windows 10 (Legacy) partition, the System Reserved partition (F:) and 417GB Unallocated space. The flash drive with the latest redstone version (FCU) is ready to go. Please explain the /Sources folder and why I should run setup.exe from there. I can learn something from an explanation. BTW, I used Mini-Tool Partition Wizard.

On your Windows 10 USB flash drive you should have a sources folder. I think it was @Kari that showed me this. If you run setup.exe from the root of the USB flash drive, it won't let you do a "clean" install. It will only let you do an upgrade or repair install of an existing Windows installation. Under the sources folder of the USB flash drive (or mounted ISO file), there is also a setup.exe. Running that one from within Windows will allow you to do a "clean" install of Windows 10 into a separate space or partition of the drive.

So, to do a clean install of Windows 10 to your unallocated space that you now have, you need to either boot the computer from the USB flash drive, or within Windows, double click on the sources folder, then setup.exe.

If neither one of those options work, you can create an NTFS partition in the unallocated space, assign a temporary drive letter to it, then use the DISM /APPLY-IMAGE command to apply the proper version of Windows 10 contained in the \sources\install.esd file on the USB flash drive to the partition you created. Then you add that Windows image to the boot menu with the BCDBOOT command.

NavyLCDR said:

On your Windows 10 USB flash drive you should have a sources folder. I think it was @Kari that showed me this. If you run setup.exe from the root of the USB flash drive, it won't let you do a "clean" install. It will only let you do an upgrade or repair install of an existing Windows installation. Under the sources folder of the USB flash drive (or mounted ISO file), there is also a setup.exe. Running that one from within Windows will allow you to do a "clean" install of Windows 10 into a separate space or partition of the drive.

So, to do a clean install of Windows 10 to your unallocated space that you now have, you need to either boot the computer from the USB flash drive, or within Windows, double click on the sources folder, then setup.exe.

If neither one of those options work, you can create an NTFS partition in the unallocated space, assign a temporary drive letter to it, then use the DISM /APPLY-IMAGE command to apply the proper version of Windows 10 contained in the \sources\install.esd file on the USB flash drive to the partition you created. Then you add that Windows image to the boot menu with the BCDBOOT command.

I used the trick of using setup.exe in the sources folder last week and it definitely works to give you the option of a clean install.

Respectfully, @topgundcp, my post was not referring to running setup.exe in a WinPE environment. It was referring to running setup.exe from a fully installed and running Windows environment. I believe that was a misunderstanding. From your normal, fully installed and running Windows, run setup.exe from the root of a Windows 10 USB flash drive or mounted ISO file and you get no option to do a clean install to a blank space on your hard drive or SSD - you only get the option to re-install (or upgrade) over the existing running Windows installation.

Now from your normal fully installed Windows run setup.exe that is in the /sources folder and you will see that you get the normal initial Windows setup screens just as if you had run it from within a WinPE environment. That allows you to do a clean install to a separate partition for a dual boot Windows, which running setup.exe from the root folder does not.

Good catch about @Nisko's C: drive being marked as active, I missed that.