First download windows 10 Technical Preview, if you are not sure how to do that follow my previous article on How to download Windows 10 Technical Preview ISO.

Now that you have the ISO image we can install it in two ways,

Option 1: You can upgrade your existing Windows 8 Operating system and land on the Windows 10 Technical Preview, but this is not recommended since this is just a technical preview and you are just going to explore the new features. Also rolling back your Windows 10 may also be a tedious job to do.

Option 2: You can setup an isolated sandbox environment using Oracle VirtualBox which will not impact your existing windows installation.

In this article we are just going to focus on Option 2, install and setup Windows 10 on Oracle VirtualBox. So let us go ahead and get started.

Before you follow the instructions make sure you have the following with you,

Windows 10 Technical preview ISO image

Oracle VirtualBox to run Windows 10

Virtual Clone Drive to mount the ISO

Note: If you have VirtualBox version 4.3.16 or less you might(I am not saying you will) face some issues so it is better to download and Install version VirtualBox 4.3.18 since it explicitly states in the change log that there are some tweaks that are added for Windows 10.

Steps to Install Windows 10 on VirtualBox

First install Virtual Clone Drive and Oracle VirtualBox in your system and then follow the below steps:

Right-click on the Windows 10 Technical preview ISO file and select the option, Open with -> Mount Files with Virtual Clone Drive (or) right click the Virtual Clone Drive icon in your Task-bar and select the Drive you have and click Mount… option.

Now choose the ISO file, it should be mounted and you should see the AutoPlay option. Just close the AutoPlay option since we are going to install it in our VirtualBox only.

Now open Oracle VirtualBox, go to Machine Menu and click New or use the shortcut CTRL + N to bring the Create Virtual Machine Dialog.

In the Name and Operating System section enter the Name as Windows 10 Test Machine and select the version as Windows 8.1 (64 bit) as shown in the above screenshot and click Next.

Note: I selected the 64 bit version because I had downloaded the x64 version of Windows 10 Technical Preview.

You will be now asked to specify the Memory size (RAM) for your machine. The recommended RAM size to run Windows 10 is 1 GB for 32 bit machines (x86) and 2 GB for 64 bit machines (x64), depending on the amount of RAM you have you can allocate it. Click Next.

Leave the Create a virtual hard drive now option as it is and click Create button.

Choose the Hard drive file type as VDI (VirtualBox Disk Image) which is the default option and click Next.

Leave the Dynamically allocated option as it is and click Next.

Now you can specify the location where you want to place this Virtual Machine and how much space you want to allocate to it. The recommended disk space size is 16 GB for Windows 10, specify double the amount so that you can also use it for other purposes. Click Create.

You should now see that your VM ready, click on the Windows 10 Test Machine and click the Start arrow button.

If you see “Fatal: No bootable medium found! System halted.” message as shown below then it means that your ISO drive is not properly selected. Press the shortcut key Windows + E to launch My Computer and see which drive holds your ISO image that you mounted using Virtual Clone Drive. Now click on the Devices Menu and select the Drive which has the ISO file, in my case it is Host Drive ‘G:’.

Next Go to the Machine menu and click Reset button.

In the following Virtual Box Question dialog again press Reset button.

You should be able to see that the Windows 10 Installation setup started. Pick the preferred language and click Next.

In the next screen click on the Install now button.

You will be presented with the License Terms select the “I accept the license terms” check-box and click Next.

For the which type of Installation do you want? question select Custom: Install Windows Only (advanced) option as show below:

Next you will see the disk space that you have earlier allocated before you began the installation of Windows 10. You don’t have to do anything here, just click Next.

You should now see that your Windows 10 installation has started.

Note: It may take a while to move away from the below Windows 10 Getting Ready message, so please be patient.

The virtual machine will be restarted automatically and then you should be able to see the below Setup screen. Click on the Use express settings button.

You will be asked to sign in to your Microsoft Live account, provide the id and password that you used to register for the Windows Insider Program. Click Next.

You will be asked to verify your account as part of safety measure, enter the correct email and click Next.

You will receive a code in the alternate email id that you have correctly provided, enter that code as shown in the below screenshot and click Next.

After some pretty cool interesting messages are shown to you,

Your Windows 10 Desktop is ready for you to use

Over to You

That’s it, you have now successfully installed Windows 10 on VirtualBox I wrote this article when i was setting up my own Windows 10 Technical Preview on Virtual Box, so if you found something missing/needs correction please feel free to hurl them down in the comments section. Got questions or feedback? You now know where to leave them