How to dual boot Windows 10 with Windows 8.1

Posted on Apr 22 2015 - 7:26am by Ajay Singh

If you want to test Windows 10 technical preview but don’t want to remove the current Windows 8.1 running on your PC you can dual boot it. Dual booting Windows 10 Technical preview will easily allow you to test the Windows without any issues and use Windows 8.1 simultaneously. Microsoft is trying to work out a solution using which users can test Windows 10 technical preview and one of the successful ways which you can try is by dual booting.


The technical preview of Windows 10 still comes with many bugs and all the features don’t work till date so we suggest you not to use the technical preview of Windows 10 as your primary operating system which leaves as dual booting the only and best option. There are many ways using which you can test Windows 10 technical preview without doing anything to the current operating system but the best one is dual booting. The main reason behind choosing dual booting is it will allow the operating system to take control of the hardware of your computer. If you are using a virtual machine you won’t be able to achieve this status.

In this tutorial we will focus on creating dual boot system on a computer having a single hard drive and for that we will use disk management utility. Disk management utility will help you in creating a new partition to install Windows 10 technical preview.

You can also dual boot windows by creating a dual boot system image using virtual disk but there is one big issue associated with it and that is there is no option to update to new releases of the technical preview of Windows 10. There is no option for updates under virtual disk image. If you want to update to new version of Windows 10 technical preview you need to delete all data and then do a new installation of the update.

Pre Requisites

You need to fulfill the following pre requisites before we start the procedure to dual boot Windows 10 with windows 8.1

  • A PC with Windows 8.1 running on it.
  • 20 GB of HDD space or more.
  • Create backup of your Windows 8.1 PC before you start the process.
  • Knowledge of using a secondary hard drive.
  • Windows 10 Technical Preview copy.
  • USB Flash Drive.

Minimum system Requirements

Your system should pass these requirements if you want to dual boot Windows 10.

  • 1 Ghz processor of faster.
  • 1 GB Ram for 32 bit processor and 2 GB Ram for 64 bit processor.
  • Microsoft DirectX 9 graphics card with WDDM driver.

Making recovery backup

Before you start the dual booting process make sure you are having a backup of computer so that if anything happens to your Windows 8.1 you can rollback the changes. You need an external hard drive with free space to save all the files for this purpose.

  1. First of all right click on the Start menu and then open Control Panel.
  2. Once in Control Panel open System and Security. Once in System and Security go to File History.
  3. You will find System Image Backup option in the bottom let corner, open it.
  4. Now start the backup process and connect external hard drive to your computer. Follow the on-screen instructions to start the backup process and click on Start backup which will start the process.

Once the complete backup of Windows 8.1 is completed you can disconnect the external hard drive from your computer.

Getting installation Files

You have now created backup of your Windows 8.1 and the next phase is getting the installation files.

  1. First of all you need to register to Windows insider. Go to this link to register for Windows Insider and you also need a Microsoft account at this point.
  2. After registering for Windows Insider go to this link. Download the latest ISO image for Windows 10 technical preview from this link.
  3. Make sure you choose the correct architecture as per your PC (32 bit or 64 bit). Once selected click on Download button.
  4. Once you have downloaded the ISO file, you need to download Windows USB Download tool. You can download the tool from this link. Windows USB Download tool will help you in creating a bootable USB device from the ISO files you downloaded. Simply follow the on-screen instructions and you will be able to create a bootable DVD disc or Flash drive.

Making space for new OS

Here in this section we will adjust the Windows 8.1 partition which will make some space for Windows 10 Technical Preview.

  1. First of all right click Start button and from there click on Disk Management option.
  2. Once in Disk Management right click on the C Drive and then choose Shrink Volume.
  3. Now disk management utility will analyze your hard drive. From here you will find out how much space you can shrink in the hard drive. Allocate at least 20 GB space for making a new partition.
  4. Once you have allocated the space click on Shrink button.
  5. You will see a new section with new unallocated space written on it. Right click on unallocated space option and then choose New simple Volume option. This will launch utility which will help you in creating a new partition. Follow all the on-screen instructions, select all the options to default while you are creating a new partition. Use NTFS file system for creating the new partition.

Changing BIOS boot order

We are going to use USB flash drive to install Windows 10 technical preview and for that we need to make sure that the boot order is correct. To enter the BIOS of your computer you need to reboot your computer and repeatedly press the (F1, F2, F3, F10 or the ESC Key)

Once you are in the BIOS menu go to Boot section and change it to Windows 10 Installation media. If your computer us using UEFI Bios you need to perform extra steps to go into BIOS menu. PC Settings > Update and recovery > Recovery > Advanced Startup and click Restart now.

You will go to the boot menu. From there on go to Troubleshoot > Advanced options > UEFI Firmware Settings > Restart. Your computer will boot into BIOS menu from where you can easily change to boot order as per your preference.

Installing Windows 10 Technical Preview along with Windows 8.1

Follow the steps shared below if you want to install Windows 10 Technical Preview along with Windows 8.1

  1. Connect the USB Drive to your PC and reboot your PC.
  2. You will see “Press any Key to start” Simply press and key and Windows Setup will start on your computer. Click on Next followed by Install Now.
  3. Accept the License terms and then click on Next option.
  4. On the next page you will see two options. One being Upgrade and other one being Custom. Click on Custom option.
  5. Now you have to select the new partition which you created. If you have not assigned any name to the partition earlier it should be named as New Volume. As we selected a 20 GB partition so you will see the Free space as 20 GB only. Select the partition and click Next button which will start the dual booting installation process.
  6. Your PC will reboot a couple of times during installation and at the boot menu you will be asked to choose an operating system. Select Windows Technical Preview and the installation process will continue.
  7. Once the installation of Windows 10 Technical Preview is completed, complete the OBBE which will finish the installation process.

You have successfully installed the Technical Preview of Windows 10 on your computer. Windows 10 will now try to install the drivers for your computer automatically. If you are having trouble in installing the drivers you can manually download them and install them on your PC.

If you want to go back to Windows 8.1 you can reboot your computer and select Windows 8.1 as your operating system from there.

Removing Windows 10 Technical Preview

If you want to use Windows 8.1 only you can delete Windows 10 Technical Preview as it will only add to extra space on your hard drive. Follow the steps to delete Windows 10 Technical Preview from your computer.

  1. Reboot your PC and boot in Windows 8.1
  2. Once you are in Windows 8.1 type MSconfig, hit Enter and then go to Boot.
  3. Choose Windows Technical Preview option from there and then click on Delete button. The boot menu will be removed once you click on Delete button. Click Apply followed by Ok.
  4. Now open the Disk Management and right click the partition where you installed the technical preview of Windows 10. Choose delete volume option and then Yes
  5. All the unallocated hard drive space will go back to Windows 8.1 partition. Right click on the partition where you are using Windows 8.1 and then select Extend Volume option. Use all default settings and the process will be completed.

You have successfully removed Windows 10 Technical Preview from your Computer.

Let us know how you are using Windows 10 Technical Preview on your PC.

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