How to dual-boot Windows 10 Technical Preview along with Windows 8.1

If you want to test the Windows 10 Technical Preview version, then creating the dual-boot system alongside Windows 8.1 is the safest way. Microsoft has changed things in Windows 10 as it is allowing the users to download and install the previous OS versions, so users get a sneak peek of what is to come. This also helps the company to get more feedback and design the OS according to the users wish.

However Windows 10 is still in beta version, it has lot of bugs and there are many feature that don’t work. So it is not recommended to use it as the primary Operating System. Though there are different ways to test the Windows 10 Technical Preview without effecting your current installation, dual-boot is one of the best way to do so. Here in this article we are going to show you how to create the dual-boot system on computers which have only one hard drive. For this we use Disk management utility to create new partition for Windows 10 Technical Preview.

It is worth to opt to create the dual-boot system using the virtual disk, but there is a problem with this, you can’t install new updates in Windows 10 Technical Preview. In this way you need to delete and again create a new installation for every new update released.

How to dual-boot Windows 10 Technical Preview along with Windows 8.1

System Requirements

  • PC running on Windows 8.1
  • 20 GB of free hard disk space
  • Complete backup of the PC running on Windows 8.1
  • Copy of the latest build of the Windows 10 Technical Preview
  • An USB flash drive
  • 1 GHz or faster processor
  • 1 GB RAM for 32-bit CPU or 2 GB RAM for 64-bit CPU
  • Microsoft DirectX 9 graphics device with WDDM driver

Create Recovery backup

Before dual-booting Windows 10 Technical preview alongside Windows 8.1, you need to create the full system image backup. If something goes wrong then you can restore this backup.

  • Right click on Start button and select control panel option.
  • Here navigate to System and Security and click on File History.
  • Now you will find System Image Backup option at the bottom-left corner.
  • Connect an external hard drive and start the backup utility. Follow the onscreen instructions and click on Start Backup to start the process.
  • After completing the backup process disconnect the external hard drive.

How to get installation files

  • Register as a Windows Insider from here using your Microsoft account.
  • After registering, click here to download the latest version of ISO for Windows 10 Technical Preview.
  • Choose the correct language and architecture and click on Download.
  • After downloading Windows ISO file, download and install Windows USB/DVD download tool, which let you create a bootable USB or DVD installation media from the ISO file which you have downloaded.

Allocate space of new OS

Here we are going to adjust the Windows 8.1 partition to allocate space for Windows 10 Technical Preview.

  • Right click on Start button and click on Disk Management option.
  • Here right-click on the C drive and select Shrink volume option.
  • Now disk management utility will analyze the hard disk for few seconds and show how much space it can shrink. Here make sure to allocate at least 20 GB for the new partition and click on Shrink button.


  • Now you can see the new un-allocated space. Right click on it and select New Simple Volume to launch an utility to create the partition. Follow the on screen instructions to create a new partition using NTFS system file.

Change BIOS boot order

Before installing the Windows 10 Technical Preview without effecting Windows 8.1 installation, make sure that your PC can boot from USB or DVD drive. To launch this process you need to hit any of F1, F2, F3, F10, F12, ESC or Delete keys. Once you are in the BIOS screen, find the BIOS section as it change it to Windows 10 Installation media.

If your PC is using UEFI BIOS, then you can’t access BIOS so easily. For this go to PC Settings > Update and Recovery > Recovery > Advanced Startup and click on Restart Now option. Now Windows will take you to the boot menu and here go to Troubleshoot > Advanced Settings > UEFI Firmware settings > Restart. Windows 8.1 will now boot into BIOS and here it will give you access to the boot order of the system.

Install Windows 10 alongside Windows 8.1

  • Insert the DVD or connect USB flash drive into your PC and reboot the system.
  • Press any key to start the setup and then click on Next and Install Now.
  • In the next screen accept the license terms for Windows 10 Technical Preview and click on Next and then click on Custom option.
  • Here select the new partition which you have created and click on Next to begin the dual-boot installation process.
  • During installation process, you will find a new boot menu at startup, which gives the option to boot to Windows 8.1 or Windows 10 Technical Preview. Click on the Windows 10 Technical Preview to continue the installation process.

windows 10 and 8.1

  • After completing the installation, follow Out-of-Box-Experience to complete the installation process.

That’s it, you have configured dual-boot system running on Windows 10 Technical Preview alongside Windows 8.1. Whenever you want to boot into Windows 8.1, then restart your computer and during boot, select Windows 8.1 from the menu.

How to get back to only Windows 8.1

After using Windows 10 Technical Preview, if you want to delete it from your system and want to use only Windows 8.1 then follow the below steps,

  • Reboot your PC and boot into Windows 8.1.
  • Press Win+ R keys to open RUN command and type MSConfig and press Enter and navigate to the boot window.
  • Here choose Windows 10 Technical Preview and click on Delete option. This will remove the boot menu when you restart your PC and this will make Windows 8.1 as your default Operating System and click on Apply and OK buttons.
  • Now open Disk Management and then right click on the partition which has Windows 10 Technical Preview installed and select Delete volume and click on Yes to confirm.
  • Now this freed unallocated space will go back to the Windows 8.1 partition. Now right click on the Windows 8.1 partition and select Extend Volume option. This will open a wizard and here use all the default settings and complete the process.

That’s it, restart your computer and your computer looks like before as you have never installed Windows 10 Technical Preview on it.

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