What is Windows Sandbox?

With Windows 10 Insider Preview Build 18305, Windows Sandbox is introduced. Windows Sandbox is a new lightweight desktop environment meant for safely running applications in isolation.

Many a times we download an executable file but are unsure whether it’ll be safe to run it or not. For this Microsoft has developed Windows Sandbox. its an isolated, temporary, desktop environment where you can run untrusted software without the fear of lasting impact to your PC. Any software installed in Windows Sandbox stays only in the sandbox and cannot affect your host. Once Windows Sandbox is closed, all the software with all its files and state are permanently deleted.

Features of Windows Sandbox:

• Part of Windows: Everything required for Windows Sandbox comes with Windows 10 Pro and Enterprise. Downloading VHD is not required.
• Pristine: Every time Windows Sandbox runs, it’s as clean as a brand-new installation of Windows.
• Disposable: Nothing persists on the device; everything is discarded after you close the application.
• Secure: Uses hardware-based virtualization for kernel isolation, which relies on the Microsoft’s hypervisor to run a separate kernel which isolates Windows Sandbox from the host.
• Efficient: uses integrated kernel scheduler, smart memory management, and virtual GPU.

Installing Sandbox:

• Install Windows 10 Pro or Enterprise Insider Build 18305 or newer.
• Enable Virtualization :
• If you are using a physical machine, ensure virtualization capabilities are enabled in the BIOS.
• If you are using a virtual machine, enable nested virtualization with this PowerShell cmdlet: Set-VMProcessor -VMName <VMName> -ExposeVirtualizationExtensions $true
• Go to Settings > Apps > Apps & Features > Programs and Features > Turn Windows Features on or off, and then select Windows Sandbox. You might be asked to restart the computer.
• 
• Using the Start menu, find Windows Sandbox, run it and allow the elevation
• Copy an executable file from the host
• Paste the executable file in the window of Windows Sandbox (on the Windows desktop)
• Run the executable in the Windows Sandbox; if it is an installer go ahead and install it
• Run the application and use it as you normally do
• When you’re done experimenting, you can simply close the Windows Sandbox application. All sandbox content will be discarded and permanently deleted.

Prerequisites for using Windows Sandbox:

• Windows 10 Pro or Enterprise Insider build 18305 or later
• AMD64 architecture
• Virtualization capabilities enabled in BIOS
• At least 4GB of RAM (8GB recommended)
• At least 1 GB of free disk space (SSD recommended)
• At least 2 CPU cores (4 cores with hyperthreading recommended)

Windows Sandbox internals:

Windows Sandbox is built on the technologies used within Windows Containers. Windows containers were designed to run in the cloud. So taking that technology, it was integrated with Windows 10 and built features that make it more suitable to run on devices and laptops without requiring the full power of Windows Server.

So if you are interested, install and try running applications in Windows Sandbox.

For some known issues, please check this.

For more details on Sandbox internals, please check source.