Windows XP

1. Windows XP

2. History • Windows XP is based on the NT kernel developed in 1988 • XP was originally sold as an upgrade from Widows 2000 or a replacement for Windows 95/98 • XP was the first Windows OS to have a 64 bit version.

3. Design Principles • What is better than the past C-2 classification of Windows NT 4.0? • Security goal • What was the result of manual and automatic code reviewing of the lines of code? • Improvement in reliability requirements

4. Design Principles • what is the purpose to be able to run both business and consumer applications with the use of another layer (of Windows)? • Improve application compatibility • what was the kind of computers Microsoft was intending high performance for? • Desktop, server, multithreaded, and multiprocessor computers

5. Design Principles • what is the reason of extensibility using layers? • Preparation for advancing • how is Windows XP designed to be capable of running programs that were developed for previous Windows versions? • Environmental Subsystems

6. Design Principles • what is the reason why new installations of things such as hardware can be made in Windows XP without affecting the executive? • Modular structure • what is the ability for the architecture of Windows XP to work for different hardware with the minimum amount of changes made? • Portability

7. Design Principles • what is hardware-abstraction layer, which Windows XP is based around instead of the certain hardware the computer has? • HAL • what is the programming which uses Unicode characters to change the language it would need to be used for? • National Language Support

8. Environmental Subsystems • What are Environmental subsystems • User-mode processes that enable Windows XP to run programs developed for other operating systems • XP uses the Win32 API subsystem as the main operating environment

9. How do Environmental Sub Systems work? • When an application begins the VM manager loads the application’s executable code and returns a status to Win32 indicating the type of executable • Then the appropriate sub system takes control over the application’s start up • Environmental sub systems are mutually exclusive

10. MS-DOS Environment • Run by the Virtual DOS Machine (VDM) • Uses an Instruction execution unit to execute or emulate Intel 486 instructions • Windows XP command shell creates a window that emulates the DOS command line interface • Can run both 16 and 32-bit executables • Not all DOS applications run under the VDM • The non-multitasking nature of DOS can cause some behavioral issues with some programs

11. 16-bit Windows • Uses a VDM that implements additional software called “Windows on Windows” • Can multitask with other processes on XP, but only one Win16 application may run at a time • All Win16 applications are single threaded, reside in the same address space, and share the same input queue • Multiple Win16 environments can be created using the command line • Some Win16 applications will not run in this environment

12. 32-bit Windows on IA64 • Uses a thunking layer to translate 32 bit addresses and system calls into 64 bit • Implementations between 32 and 64 bit Windows are virtually identical

13. Win32 Environment • This is the main subsystem for Windows XP • Runs Win32 applications and manages all keyboard, mouse, and screen I/O • All processes have their own input queue • Provides preemptive multitasking • Validates all objects before using them • Allows a shim layer to improve compatibility with Windows 95/98 at the expense of performance

14. POSIX • POSIX is based on the UNIX model • POSIX processes can be started by the Win32 API or another POSIX • Support for POSIX applications is not present in Windows XP Home, but is present in the Professional version

15. Login and Security Subsystems • WINLOGIN is the authentication service for Windows XP • Only WINLOGIN can intercept the secure attention sequence (control+alt+delete) • Calls a authentication package to authenticate login

16. Networking • who were the developers of network device interface specification (NDIS)? • Microsoft and 3Com • what are drivers to be loaded/unloaded to the system? • Implemented transport protocols • what is a protocol used to share files and printers with Apples? • AppleTalk protocol

17. Networking • what is the socket APL that Windows XP uses so that it is compatible with UNIX sockets? • Winsock • what is the ability of sharing with a remote computer in the form of a local connection? • Redirector and server capabilities • what is the ability to change user on various machines with using folder redirection on a server so that it is the same? • Roaming profiles

18. Networking • what is the order that gives access/shared and restriction to the computers on the domains? • Result of hierarchical trusts • what are the three types of trust relationships that Windows XP is capable of? • One-way, transitive, and cross-link

19. Networking • what are the active directory that Windows XP uses to remember passwords and administrator capabilities? • Group policies and intellimirror • what is one of the ways of name resolution is preformed only in Windows? • Windows internet name service (WINS)