| Microsoft began with the desktop. The modern Windows environment has become ubiquitous. Countless applications are available, and most computer users are at least somewhat at home with Windows. While Microsoft has made much progress in modernizing Windows, there are still significant problems. Problems with Windows Maintaining a Windows PC is a chore, because applications are quite complex. They consist of many files, Registry entries, shortcuts, and so on. Different applications can share certain DLLs, and installing a new application can overwrite a DLL an existing application depends on, possibly breaking an old application (DLL Hell). Removing an application is a complex operation and is often imperfectly done. A PC can gradually become less stable, sometimes requiring the drastic cure of reformatting the hard disk and starting from scratch. While there is tremendous economic benefit to using PCs, because standard applications are inexpensive and powerful and the hardware is cheap, the savings are reduced by the cost of maintenance. Windows was originally developed when personal computers were not connected over a network and security was not an issue. While security was built into Windows NT and Windows 2000, the programming model is difficult to use. The Glass House and Thin Clients The old "glass house" model of a central computer that controls all applications has had an appeal , and there has been a desire to move toward "thin clients" of some sort . But the much heralded "network PC" never really caught on. There is too much of value in standard PC applications. Users like the idea of their "own" PC, with their data stored safely and conveniently on their local computer. Without broadband connectivity, a server-based application such as word processing would not perform very well. Security is also a very difficult issue to solve with thin clients. The personal computer is undoubtedly here to stay. A Robust Windows With all the hype about .NET and the Internet, it is important to realize that .NET has changed the programming model to allow the creation of much more robust Windows applications. Applications no longer rely on storing extensive configuration data in the fragile Windows Registry. .NET applications are self-describing , containing metadata within the program executable files themselves . Different versions of an application or component can be deployed side by side. Applications can share components through the Global Assembly Cache. Versioning is built into the deployment model. A straightforward security model is part of .NET. Windows Forms technology is a new paradigm for building Windows GUI applications.  | 
