Windows system is one of the most popular operating systems in the world. Since it first launched in 1985, it has undergone many improvements and updates.
It uses an elaborate, software virtual memory scheme that lets it run applications larger than available RAM. Code and resource segments are swapped in when needed, and moved out when the application relinquishes processor control.
Windows NT
The Windows NT family of operating systems from Microsoft is a multiprocessing, 32-bit OS developed for servers and workstations. It features built-in networking and preemptive multitasking. NT also supports domains, which allow centralized administration of users and computer resources over a network.
The kernel of a NT operating system performs basic functions like thread dispatching and hardware exception handling. It does so in a very efficient manner, freeing CPU cycles for application programs. Hardware-specific code is kept in a layer known as the hardware abstraction layer (HAL), which simplifies porting to new processor architectures.
A user-mode subsystem called Win32 provides a standard API to system services and applications. For instance, a device driver can extend the functionality of a HAL-based file system to support a new type of disk drive or memory bus. Win32 applications are preemptively multitasked, so no single program can monopolize system resources. The NT Registry is a valuable, efficient storehouse of various types of data.
Windows 2000
One of the more notable new features of Windows 2000 is its ability to pinpoint text and file properties with impressive speed. This feature isn’t enabled by default; you must first create an index of the system files to harness its power.
Touted by Microsoft as its most stable version ever, Windows 2000 brought Group Policies forward from NT and enhanced what could be controlled from a central system with the introduction of Active Directory, a modern directory service that locates resources in a database and allows finely-grained controls. It also introduced NTFS 3 and an on-the-fly Encrypting File System.
The Windows 2000 family includes four editions: Professional, Small Business Server, Advanced Server and Datacenter Server, each targeted for specific markets. The server versions of the OS include additional features such as a domain name server which can register dynamic IP addresses, and LDAP (Lightweight Directory Access Protocol). The operating system supports plug-and-play devices, has improved support for people with disabilities over NT 4.0 and increased language and locale settings.
Windows XP
XP is the consumer edition of Windows NT and received acclaim from users and critics upon its release in 2001. The operating system offers an intuitive user interface, better hardware support and expanded multimedia capabilities.
The operating system supports a maximum partition size of 5 gigabytes (5120 MB). It uses the NTFS file system, which allows for a larger amount of disk space and provides security features at the file level.
The operating system also includes a built-in firewall that protects the computer from unauthorized incoming connections and blocks outgoing connections. Those who wish to use XP can install and run most software applications that are compatible with the OS. However, many independent software vendors have stopped providing updates for their products to support XP. This means that the operating system may not receive critical security updates. Some users may also experience issues with some hardware drivers and printers. However, the operating system can still be used on a number of different computers.
Windows 7
Windows 7 is a follow-up to the popular Vista operating system. It is available in a number of editions including Starter, Home Basic, Home Premium, Professional, and Enterprise.
It supports touch screens, recognizes USB devices faster, and runs a little bit faster than Windows XP on a similar hardware configuration. In addition, it introduces a feature called Aero Snap that allows two programs to be displayed side-by-side on the screen.
Microsoft touts a number of other features including better previewing, easy sharing through HomeGroup, and media streaming capabilities. It also claims that Windows 7 performs better than Windows XP or Vista on the same hardware. It supposedly sleeps and resumes faster, uses less memory, and is more stable than previous versions of the OS. It also dispenses with glitzy effects and naggy UAC (User Account Control). This makes it easier to work on the computer without being constantly pelted with pop-up alerts or warnings. It is also able to boot and run fine on older, legacy hardware.