Have you ever seen a Operating System inside a browser? Have you ever seen a Internet Explorer inside a Firefox Browser? Maybe you have recently moved to Linux/Mac operating system from Windows but you are missing familiar interface and want to spend some time on Microsoft Windows but don’t have access to it, if this is scenario for you then here is windows4all.com.
Windows4all.com is a Silverlight based online virtual operating system (sometimes called a Web OS or a Webtop or a cloud computer). 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. It can give you a familiar work interface that looks the same whether you’re working at your home computer, or remotely from a borrowed or public computer. 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 your file system or doing anything that could hurt your machine. Besides desktop, taskbar, start menu and sidebar, currently it includes such applications:

• File Explorer
• Internet Explorer
• Video Player
• Rich test editor
• RSS reader
• Virtual PC
• Notepad
• Paint
• Chat
• Calculator
• Games like Chess, Solitaire, Spider etc.e

The system also supports installing program functionality. But this program should be developed in Silverlight and be available in Internet or local file system.
Windows4all.com advantages:

• Convenience and freedom - A personalized desktop is available and accessible from any computer in the world.
• No more administration - No more software installation, software update, worry about anti-virus.
• Security - Less prone to typical attacks, viruses, worms, vulnerabilities, spyware and disk crashes.
• Hardware - Performance doesn't depend much on the speed of your computer.
• Entertainment - Being online, windows4all.com offers more opportunities for communicating and entertainment.
• Cost - It is free.

This content requires Microsoft Silverlight.