Have you ever downloaded an executable file (.exe file) but are afraid to run it, fear that running it might just blow off your whole system? You wish you can have a test machine, or better, a virtual machine for you to try out but also don’t feel like setting up one from scratch. Microsoft is trying to address this fear with a new feature called Windows Sandbox.
It’s designed to be secure and disposable, running as an isolated, temporary, desktop environment where you can run untrusted software without the fear of losing anything in your main computer. Anything installed in Windows Sandbox stays only in that sandbox and will not affect your main computer in any way. Once you are done with the test, simply close Windows Sandbox. Anything installed in the sandbox, along with any its files will be permanently destroyed.
Requirements to run Windows Sandbox
In order to utilize this cool new feature, you will need a computer that
- runs Windows 10 Pro or Enterprise build 18305 or later, 64-bit edition.
- has virtualization capabilies enabled in BIOS
- has at least 4GB of RAM, 1GB of free space and 2 CPU cores.
Once all qualified, move on to enable it.
How to enable Windows Sandbox
Click Start menu, type “Windows Feature”, and click “Turn Windows features on or off” that pops up.
Check Windows Sandbox option in Windows Features window, and click OK
Once finished, restart your computer and you are all set.
How to use Windows Sandbox
Once installed, Windows Sandbox appears just like a typical desktop app that you can search and find right from the Start menu.
When launched, it runs just like another virtual machine that runs on top of your current system, except that the system in the sandbox is basically the brand new fresh version of your main system. From there, you can copy and paste the executable files over and run inside it.
Behind the scene
Built on the technologies used with Windows Containers, Windows Sandbox is a lightweight virtual machine that mimics the copy of the Windows 10 system installed on your computer, using what’s called Dynamic Base Image, a mix of clean copies of files that can change and links to files that cannot change in the main Windows host. Therefore, the size of the sandbox virtual machine is only 25MB when not installed and will be increased to 100MB when installed.
For more information, check out this post on Windows Kernel Internals.
How come it’s not working?
First of all, check to make sure Virtualization is enabled on your system. You can find out by going to Performance tab in Task manager.
If all requirements are met, let’s go check if you have this KB4483214 update installed. Apparently, it breaks Windows Sandbox while trying to fix other bug. Go to Installed Updates in Control Panel, right-click the patch and Uninstall. Restart the computer and Windows Sandbox will be working again.