This presentation is about the introduction, history and inner supporting managing system of Operating System. how Process Scheduling and file management works by Windows.

1. Windows Operating
System
WINDOWS FOR EVERYONE

2. Group Members
Sadain Ali (42440)
Muhammad Waleed Khan (42453)
Abdul Rehman (42767)
Syed Hassan Shah (42321)
Syed Asad Abbass Zaidi (43700)
Usama Sabzwari (43273)

3. Content
 Introduction to Windows
 History & Development
 Process Scheduling
 Memory Management
 File Management
 Most Common Features
 Function of an Windows(OS)

4. Introduction
 Developer: Microsoft
 Initial release: 20th November, 1985; (34 years ago, as version 1.0)
 Marketing target: Personal computing
 Available in 138 languages
 Default user interface: Windows shell & GUI
 License: Proprietary commercial software
 Official website: windows.microsoft.com

5. Introduction
Before Coming Windows:
PC users relied on the MS-Dos method of typing command at the C prompt
(C:)
With Windows:
 User move a mouse to point and click their way through tasks, such as
Starting Application.
 In Addition, windows users could switch among several concurrently
running application.

6. Introduction
Windows:
 Windows is an Operating System which makes the Computer System Work
& User Friendly.
 Without Windows(Operating System), you can’t Operate Computer such as
the system unit, monitor and the keyboard.

7. History & Development

8. Process Scheduling
 Single CPU Scheduling
 First Come, First Served (FCFS).
 Shortest-Job-First (SJF).
 Priority Scheduling.
 Round Robin (RR).
 Multilevel CPU Scheduling
 Multilevel Queue Scheduling.
 Real-time: EDF and RM.

9. Process Scheduling
 round-robin
Windows uses a round-robin technique with a multi-level feedback queue for
priority scheduling ever since NT, Though in Vista there were some smart heuristic
improvements to ensure that some processes, such as the disk defragmenter, are
at a lower priority in order to not interfer with foreground processes.
To the best of my knowledge, Windows 7 uses the same scheduler as Vista, though
there may have been minor improvements.

10. Memory Management
 Translating (mapping) a process’s virtual address space into physical memory,
so running threads correctly reference physical address
 Paging in and out contents between memory and disk when threads try to use
more memory than currently available.
 Windows uses the paging file as temporary storage for the memory dump.

11. Memory Management
Memory Allocation:
 Each region of reserved process address space begin on multiple of
allocation granularity
 Value is 64 KB
Sharing:
 Processes can also create shared memory sections.
 It does this automatically for shareable pages
E.g. code pages in an EXE or DLL
 Flexibility(Limited) & Sharing Provided by Memory Management Unit

12. Memory Management
Protection:
 protection is a way to control memory access rights on a computer, and is
a part of most modern instruction set architectures and Operating System.
 One process can’t access the memory of other process unless permission is
granted.
Logical Organization:
 Main memory is organized as linear or it can be a one-dimensional
address space which consists of a sequence of bytes or words.
 Different modules are provided with different degrees of protection.

13. Memory Management
Physical Organization:
 The structure of computer memory has two levels referred to as main
memory and secondary memory.
 Main memory is relatively very fast and costly as compared to the
secondary memory.
 Secondary memory is provided for storage of data on a long-term basis
while the main memory holds currently used programs

14. File Management
 Windows currently uses two programs to accomplish file management on
your computer.
 Windows Explorer
 My Computer

15. File management
A file is a collection of related information that is recorded on secondary
storage. Or file is a collection of logically related entities. From user’s
perspective a file is the smallest allotment of logical secondary storage.
ATTRIBUTES TYPES OPERATIONS
Name Doc Create
Type Exe Open
Size Jpg Read
Creation
Data
Xis Write
Author C Append
Last
Modified
Java Truncate
protection class Delete

16. File Management
FILE DIRECTORIES:
Collection of files is a file directory. The directory contains information about the files,
including attributes, location and ownership. Much of this information, especially that is
concerned with storage, is managed by the operating system. The directory is itself a
file, accessible by various file management routines.
Information contained in a device directory are:
 Name
 Type
 Address
 Current length
 Maximum length
 Date last accessed
 Date last updated
 Owner id
 Protection information

17. File Management
FILE ALLOCATION METHODS:
1. Contiguous Allocation: A single continuous set of blocks is allocated to a
file at the time of file creation.
2. Linked Allocation(Non-contiguous allocation) : Allocation is on an
individual block basis. Each block contains a pointer to the next block in the
chain.
3. Indexed Allocation:
It addresses many of the problems of contiguous and chained allocation.

18. File Management
NTFS:
NTFS (NT file system; sometimes New Technology File System) is the file
system that the Windows NT operating system uses for storing and retrieving
files on a hard disk.
Notable features of NTFS include:
 Support for very large files (up to 2 to the 64th power or approximately 16
billion bytes in size).
 An access control list (ACL) that lets a server administrator control who can
access specific files.
 Support for names based on Unicode.
 Data security on both removable and fixed disks.

19. Most Common Features
 Program Execution
 Providing user interface
 Handling input/output operations
 Error handling
 Memory management
 Process management

20. Function of a Windows(OS)
Process management:
 Code execution
 Context switching
 Multitasking
Device management:
 Input / Output
 Disk access
 Interrupt handling

21. Function of a Windows(OS)
Provide environment for software to function:
An OS provides an environment for software applications to function. An
application software is a specific software which is used to perform
specific task. In GUI operating systems such as Windows and macOS,
applications run within a consistent, graphical desktop environment.

22. Even after having some limitations Windows is now the
most used Operating System in the world. It has increased
GUI which attracts the user most.
Also it’s cost is cheap.
The main limitation is it not much secured like Mac OS.
Conclusion

23. Thank you
Windows For everyone