How to get Windows 10/11 dual boot?

Question

How to get Windows 10/11 dual boot?

DAVID PIKE 205

I have been using Windows 11 for a short while, but I have some applications that will only run properly on Windows 10. I understand 10 is no longer supported, but I only need it to do what it was doing before Win 11. I tried reinstalling Windows 10 from a recent installer on a jump drive, expecting to get dual boot. Instead it overwrote Windows 11 on my C: drive. How can I install Windows 11 (preferably on my D: drive) without overwriting Windows 10, and be able to choose either 10 or 11 when I start the PC. My computer is a 2025 ASUS gaming PC with lots of RAM and drive space.

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Answer accepted by question author

Ivan B 114.5K Independent Advisor

Hi ,

In this case, you will do the following: you will create a Windows 11 installation drive via USB.

Here media creation tools for Windows 11: https://go.microsoft.com/fwlink/?linkid=2156295

After downloading, run the media creation tool. You need to be an administrator to run this tool.

If you agree to the license terms, selectAccept.

On theWhat do you want to do?page, select Createinstallation media for another PC, and then selectNext.

Select the language, edition, and architecture (64-bit) for Windows 11.

Select which media you want to use:

USB flash drive:Attach a blank USB flash drive with at least 8GB of space. Any content on the flash drive will be deleted.

Logically, you have to have TPM active and Secure boot you leave it disabled initially.

From the USB flash drive, on the screen where to install, you have to select only the D partition, proceed (be careful not to choose incorrectly), and proceed again (do not create a partition). It will recognize that a boot partition already exists and will add Windows 11; logically, it will work.

Of course, you have to leave the D drive as an empty partition; if it's already created, you will delete it.

If you have any doubts, take a picture and post it here to make sure you're on the right track.

Give feedback if the information was useful or not.

Thanks

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Answer accepted by question author

Ivan B 114.5K Independent Advisor

Hi ,

In this case, do you have to disable Secure Boot to install Windows on separate partitions or disks, or are you trying to install on the same disk but different partitions?

There's also the case where you want to use Windows 10 with ESU for another year.

Thanks

Ivan B 114.5K Reputation points Independent Advisor

2025-11-18T09:29:31.14+00:00

Hi ,

Did you manage to solve the problem?

Thanks
DAVID PIKE 205 Reputation points

2026-01-07T00:33:43.6433333+00:00

After jerking me around for months, ASUS finally escalated the question to a senior support tech, and it turns out this ASUS PC doesn't allow dual boot. Sorry to waste your time.

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Your answer

Ivan B 114.5K Reputation points Independent Advisor

2025-11-18T09:29:31.14+00:00

Hi ,

Did you manage to solve the problem?

Thanks
DAVID PIKE 205 Reputation points

2026-01-07T00:33:43.6433333+00:00

After jerking me around for months, ASUS finally escalated the question to a senior support tech, and it turns out this ASUS PC doesn't allow dual boot. Sorry to waste your time.

Answer 1

DAVID PIKE 205

Wow. Thank you. That's wonderfully detailed and precise. It's now fairly late in the evening here (Vancouver), so I'm going to tackle it in the morning, so as not to make mistakes. I'll let you know.

By the way, while I was answering you, Windows 10 found all my data on my hard drive, desktop and OneDrive. and connected them up. That's quite a relief and will save me hours of time. Restores a bit of my faith in Microsoft.

Will be back tomorrow.

DAVID PIKE 205 Reputation points

2025-11-19T22:25:26.1933333+00:00

Aaaargh! Took me the best part of day, and it did it AGAIN!!

Sorry, had to get that out of my system.

So now My C drive has Windows 11, which overwrote Windows 10, and I'm back to one operating system, not the one I want if I have to choose.

I noticed there's some files in the D: drive root from an earlier attempt at installation.. Could that be what's messing it up, or should I check something else? And should I reformat the D: drive and do the installation all over, this time installing Win 10? Do I need to do anything to make sure D: is not a system drive?

I have a jump drive with the Win 10 installer, but it's 9-10 months old. Should I bother downloading a new one? Where can I get that?

Sorry to bother you again, but I've got to get this thing working to get on with life. Thanks for your patience.
Ivan B 114.5K Reputation points Independent Advisor

2025-11-19T23:43:15.6233333+00:00

Hi ,

The D drive partition needs to already be logically separated, as you described. Since you already had a D drive, you already had a separate partition for installation. To confirm, if possible, access Disk Management in the search bar, take a screenshot, and post it here.

To see what happened, you don't need to create another flash drive.

Thanks

Answer 2

Thank you, Ivan B. It's a relief to talk to a human rather than an AI bot,

I'm have just one drive with multiple partitions. As of now, Windows 10 is on Partition 1 (C:), so I'd like to install Windows 11 on Partition 2 (D:).

The sequence of events is confusing and I'd like to clarify. I was happily using Windows 10 until last month when Windows just took control of my PC and installed Windows 11 over top of and replacing Win10, without informing me or giving me the opportunity to stop it. At least it migrated my data.

However I still need to use Win 10 in some situations, so I thought I could just install it as the second OS, on the D: partition. I connected my Win 10 thumb drive and restarted. But for some reason, it installed Win 10 on the C: drive, over top of and replacing my existing Windows 11, without keeping any of the data or configuration. So as of now, I have raw Windows 10 on my C: drive, an empty D: drive, and no Windows 11 at all.

So things are a little backwards and I'd like to now install Windows 11 as a second OS, on my D: drive, and leave Windows 10 on the C: drive. And of course I need to have OS choice when I start the PC.

To make sure I've got the right source, could you please give me the location of the download for the most recent installer of Windows 10 and Windows 11?

Answer 3

To set up a dual boot system with Windows 10 and Windows 11, follow these steps:

Prepare Your Drives: Ensure that your D: drive has enough space for Windows 10. You may need to create a new partition on your D: drive if it is not already set up for installation.
Backup Important Data: Before proceeding, back up any important data from both Windows 10 and Windows 11 to avoid any potential data loss.
Create Windows 10 Installation Media: Use the Windows Media Creation Tool to create a bootable USB drive for Windows 10. Make sure you have the correct version that you want to install.
Boot from USB: Insert the USB drive into your PC and restart it. Enter the BIOS/UEFI settings (usually by pressing a key like F2, F12, or DEL during startup) and set the USB drive as the primary boot device.
Install Windows 10: When the Windows 10 installer starts, choose the custom installation option. Select the partition on your D: drive where you want to install Windows 10. Make sure you do not select the partition where Windows 11 is installed (usually C: drive).
Complete Installation: Follow the prompts to complete the installation of Windows 10. The installer will set up the boot manager to allow you to choose between Windows 10 and Windows 11 at startup.
Boot Manager: After installation, when you start your computer, you should see a boot menu that allows you to select either Windows 10 or Windows 11.

If you encounter issues with the boot manager or do not see the option to select an OS, you may need to repair the boot configuration using Windows recovery tools.

References:

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How to get Windows 10/11 dual boot?

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