This is a quick guide on how to install what you need in a few steps:
4: VirtualBox will provide you with a recommended memory size; accept unless you have a specific reason for changing it. Then select ‘Create a virtual hard drive’ and click Create. Accept VDI as the file type for the drive and then choose Fixed Size for the virtual drive. Finally, click Create and wait while VirtualBox constructs your virtual drive.
5: When the drive is ready, click the Start button in the VirtualBox toolbar. You’ll see a box telling you to ‘Select start-up disk.’ Just Click the file folder next to the pull-down and navigate to the Windows 10 ISO file you downloaded in the first step and click Start.
6: Now just install Windows as normal, but make sure to choose the ‘Custom: Install Windows only (advanced)’ option when asked. As usual, the setup process may involve a few reboots, though only within the confines of the VM.
Voila! Now you should have a version of Windows 10 running inside a safe and sandboxed window. Please note although the installation appears to have completed, you will have to reboot the system manually once more. After that, you are good to go for as long as you have the preview trial.
[Image via blogs.windows]