Why an isolated desktop matters
Testing a program from an unfamiliar source always carries some risk β it might be poorly made, contain adware, or worse. Windows Sandbox runs entirely separately from your real system, using its own temporary copy of Windows, so anything installed inside it, malicious or not, has no way to reach your actual files, settings, or installed software.
What Sandbox is and isn't good for
Sandbox is ideal for a quick, one-off test of a downloaded installer, an unfamiliar script, or a browser extension before deciding whether to trust it on your main system. It's less suited to anything you need to keep β since every session starts completely fresh and closing the window erases everything permanently, don't use it for work you need to save, and copy out any files you want to keep before closing the window.
Frequently Asked Questions
Does Windows Sandbox require an internet connection to work?
No, Sandbox itself works offline, though the program you're testing inside it may still need internet access for its own features, same as it would outside the Sandbox.
Can I save files from inside the Sandbox to my real computer?
Yes, most versions support copying files between the Sandbox and your real desktop through copy-paste or drag-and-drop, but anything left inside the Sandbox when you close it is permanently gone.