One note, before we begin: I'm using the german version of this program, so some of my translations might differ from their original names. But I think, it is clear, what I'm meaning.
Alright, what does virtualization mean?
It means, that programs, you start within Sandboxie will run in a virtual environment (VE). When you close your Sandbox, everything within this VE will be deleted. You open a website and catch a virus. Close your browser and everything is gone. The virus wasn't on your computer, it was just in the VE.
Another advantage: The virus can't access your system data, because it is caught in the VE. You also can disable access for special folders. So, it's impossible to access them, while you're in your VE.
But maybe, the developers could explain it better: http://www.sandboxie.com/index.php?HowItWorks (there, you find also the download link)
If you choose to install the program, you will realize that there's a huge amount of options to configure.
Don't worry about them! When you opened the main window, simply click Configuration -
How do I start my browser within the sandbox?
In your taskbar, you see a yellow Sandboxie-
Now, your browser opens with a green border. The border signalize, that you're now within the sandbox. The icon in the taskbar changes and shows now red dots within the icon. This means, an application is running within the sandbox. After closing your browser-
You will realize, that no changes, you do within the sandbox will take effect on your computer. I did some exceptions from this rule:
Sandboxie allows direct acces to
This means, when you set bookmarks, they will be saved -
Then Applications, Web-
Because of the virtualization, it's not possible to save files on your computer, except you would save them on your desktop. After closing your browser, you will be asked, if you want to restore your downloaded files from the VE to your real system.
Developer's Website: http://www.sandboxie.com