Online Virtual Windows Operating System. Windows4all.com is a Silverlight based online virtual operating system. It is is a website that simulates an operating system inside your web browser. Windows4all.com replicates the desktop environment of a modern operating system. You can launch applications right away without installation. Windows4all.com is web-based and requires Silverlight 3 to operate. Application runs in Silverlight’s security sandbox. By default code is restricted from accessing user's file system or doing anything that could hurt user's machine. Besides desktop, taskbar, start menu and sidebar, currently it includes such applications as File Explorer, Internet Explorer, Video Player, Rich test editor, RSS reader, Notepad, Paint and more. Thanks to Web Talk