My Preffered Os

Set the Boot Sequence to CD-ROM

To ensure that your computer will read the Windows XP CD to be inserted, boot sequence should be assigned to the CD-ROM first. In most computers, this setting is already set, so you do not have to worry anymore. You can continue to format the Hard Disk if there is no problem here.

But if your computer does not read from the CD-ROM, follow these steps to set the boot sequence:

(Note: Each computer has its own BIOS screen. So, what you see may differ from your computer. However, the concept remains essentially the same)

    1. Turn on your computer.
    2. Press the F2 key (on some computers, you must press the  

        DELETE button) to launch the BIOS.
    3. In the Phoenix BIOS, select Advanced BIOS Features.

Select the Boot Sequence
In the Boot Sequence sequence, set the CD-ROM is at the top.


Format Hard Disk

    1. First, you'll see a screen with the message "Press any key to boot from CD ...". Press any button here so that the computer will start reading from the Windows XP CD.
      

    2. Consider first the message out, "Press F6 if you need to install a third party SCSI or RAID driver or. " This message is important if you install Windows XP on SATA hard disk. If yes, press F6 and insert the SATA disk that came with your motherboard. If not, ignore this message and proceed to Step 3. (Note: If you want to install Windows XP on SATA hard disk but no disk, follow these steps)
       install Windows XP

Welcome to Setup "is displayed. Press ENTER to start installing Windows XP

If you see the screen "Setup did not find any hard disk" is most likely that you are using SATA hard disk. Return to Step 2, or

   5. "Windows XP Licensing Agreement." Press F8 to proceed.
      install Windows XP
   6. If you have a hard hisk Windows XP, Setup will ask if you want   to repair the old tu Windows XP. Press the ESC because you want to install a new Windows XP.
      install Windows XP
   7. If your hard disk:
           Are new and have not had any partition, follow steps 7 to 8.
          But if it has no partition in it, proceed to step 9.
   8. Create a partition by pressing C.
      install Windows XP
   9. Determine the size of your partition and press ENTER.
      install Windows XP
  10. Choose a partition C: to install Windows XP. Note: If you have any important files and documents in the partition C:, create a backup of the data transfer to the partition D: or to the external hard drive.
      install Windows XP
  11. Press button C to agree.
      install Windows XP
  12. Choose NTFS as the file system and press ENTER.
      install Windows XP
  13. Press F to format Hard Disk.
      install Windows XP
  14. Setup will start formatting your hard disk and prepare files for the Windows XP install. Once this process is complete, your computer will restart itself.
      install Windows XP

Install Windows XP

   1. Windows XP install process begins. Click the Next button.
      install Windows XP
   2. Enter your name and click the Next button.
      install Windows XP
   3. Enter the serial number for Windows XP and click the Next button.
      install Windows XP
   4. Enter a password for the Administrator and click the Next button.
      install Windows XP
   5. In the Time Zone field, select the Kuala Lumpur and click the Next button.
      install Windows XP
   6. Setup process has begun. Wait until finished.
      install Windows XP
   7. If you have a Network Card, Setup will ask you to make choices about the Network. Just click on the Next button twice.
      install Windows XP
   8. Wait until the entire Windows XP install process is complete, and the computer will restart again.

Start Using Windows XP

   1. The first time Windows XP started, your screen resolution be amended as appropriate. Click on the OK button.
      install-windows-22
   2. "Welcome to Microsoft Windows" is displayed. Click the Next button.
      install Windows XP
   3. Select "Not right now" and press the Next button. You can re-enable Automatic Updates in the future.
      install Windows XP
   4. Windows will attempt to detect your Internet connection. You may omit this step by clicking Skip.
      install Windows XP
   5. Select "No, not at this time" so you do not need to register with Microsoft. Press the Next button.
      install-windows-27
   6. Enter your name and click Next.
      install Windows XP
   7. Click the Finish button.
      install Windows XP
   8. Now, Windows XP was installed and ready you can already start using it.
      install Windows XP

Protection And Security

·File system often contain information that is highly valuable to their users.

· Protecting information against unauthorized usage is therefore major concern of all file  

  system.

·  In the following unit we will look at a variety of issues concerned with security and

  protection.

Security Policy and Mechanism

·  The term security and protection are often used interchangeable.

·  Nevertheless, it is frequently useful to make a distinction between the general problems  

   involved in making sure that files are not read or modified by unauthorized persons, which 

   include technical, managerial, legal and political issues on the one hand, and the specific   

   operating system mechanism used to provide security on the other to avoid confusion, we will 

   use the term security to refer to the overall problem, and the term protection mechanisms to 

   refer to the specific operating system mechanisms used to safeguard information in the 

   computer.

·  The boundary between them is not well defined, however.

·  A more interesting problem is what to do about intruders.

·  These come in two varieties.

·   Passive intruders just want to read files they are not authorized or read.

·  Active intruders are more malicious; they want to make unauthorized changes to data.

·  When designing a system to be secure against intruders, it is important to keep in the  

   mind the kind of intruders one is trying to protect against.

· Some common categories are:

1. Casual prying by non technical users. Many people have terminals to timesharing systems on their desks, and human nature being what it is, some of them will read other people’s electronic mail and other files if no barriers are placed in the way. Most UNIX systems, for example, have the default that all files are publicly readable.


2. Snooping by insiders. Student, systems programmers, operators, and other technical personal often consider it to be a personal challenge to break the security of the local computer system. They often are highly skilled and are willing to devote a substantial amount of time to effort.


3. Determined attempt to make money. Some bank programmers have attempted to break into a banking system to steal from the bank. Scheme have varied from changing the software to truncate rather than round interest, keeping the fraction of a cent for themselves, to siphoning off accounts not used in years, to blackmail.


4. Commercial or military espionage. Espionage refers to serious and wellfunded attempt by a competitor or foreign country to steal programs, trade secret, patents, technology, circuit design, marketing plans, and so forth. Often this attempt will involve wiretapping or even erecting antennas directed at the computer to pick up its electromagnetic radiation.

Authentic basic concept

· A major security problem for operating system is the authentication problem.

· The protection system depends on an ability to identify the programs and processes that

   are executing.

· This ability in turn, eventually rests on our power to identify each user of the system.

·  A user normally identifies himself.

· Generally, authentication is base on some combination of three set of items: user

   possession (a key or card), user knowledge (a user identifier and password), and a user         

   attribute ( finger print, retina pattern, or signature).

·   The most common approach to authenticating a user identity is the use of user  

    passwords.

·   When the user identifies herself by user id or account name, she is asked for a

    password.

·    If the user supplied password, matches the password stored in the system, the system

   assume that the user is legitimate.

1. Password

· Passwords are often used to protect object in the computer system, in the absence of

  more complete protection scheme.

·   They can be considered a special case of either keys or capabilities.

·   For instance, a password could be associate with each resource such as file.

·   Whenever a request is made to use the resource, the password must be given.

·    If the password is correct, access is granted. Different passwords may be associated

    with different access rights.

· For example, different password may be used for reading, appending and updating a

  file.

·  Although there are some problems associated with the use of password, they are

  nevertheless extremely common, because they are easy to understand and use.

·The problems with passwords are related to the difficulty of keeping a password secret.

· Password can be compromise by being guessed, accidentally exposed, or illegally

   transferred from an authorized user to an unauthorized one.

2. Artifact

·  A completely different approach to authorization is to check to see if the user has some

    item, normally a plastic card with a magnetic stripe on it.

·  The card is inserted into the terminal, which then checks to see whose card it is.

·   This method can be combined with a password, so a user can only log in if he has

     The card

     Knows the password

·   Automated cash dispensing machine usually work this way.

·  Another technique is signature analysis.

·  The user sign his name with a special pen connected to the terminal and the computer

    compares it to a known specimen stored online.

·  Even better is not to compare the signature, but compare the pen motion made while

   writing it.

·  A good forger may be able to copy the signature, but will not have a clue as to the exact

  order in which the stroke were made.

3. Biometric Technique

·   Yet another approach is to measure physical characteristic that are hard to forge.

·    For example a finger print or a voiceprint reader in the terminal could verify the users

    identity (it make the search go faster if the user tells the computer who he is, rather then       

    making the computer compare the given fingerprint to the entire database).

·  Finger length analysis is surprisingly practical.

· When this is used each terminal has a device.

·The user inserts his hand into it and the length of all his finger is measured and check against the database.

File System Manegement

File system management objectives

A file management system is that set of system software that provides

services to users and applications related to the use of files.

include storage of data and the ability to perform the operations listed

earlier.

Concept and design

The operating system abstract from the physical

properties of its storage devices to define a logical storage unit, the file. File are

mapped, by the operating system, on to physical devices. This storage device are

usually non volatile, so the contents are persistent thru power failures and

systems reboots.

File directory

The directory is itself a file, owned

by the operating system and accessible by various to users and applications,

information is generally provided indirectly by system routines. Thus, users
cannot directly access the directory even in read-only mode

File Sharing 

Access Rights

The file systems provide a flexible tool for the following extensive file sharing

among users. The file system should provide a number of options so that the

way in which a particular file is accessed can be controlled.

To meet the data-management needs and requirements of the user, whichTo guarantee, the extent possible that the data in the file are valid

This relieves the user or programmer of the necessity of developing

special purpose software for each application and provide the system with a

means of controlling its most important asset.[GROS86] suggests the following

objectives for file management system:

Input Output Management

Input Output Procedure

A computer system uses a device controller to facilitate the transfer of information between the device and the CPU. A complex controller like small computer system interface (SCSI) may permit connecting several I/O devices simultaneously.

BUFFERING

A)    SINGLE BUFFER

The simplest time of support that the operating system can provide is single buffering. When a user process issues an I/O request the operating system assign a buffer in the system portion of main memory to the operation.  Input transfers are made to the system buffer. When the transfer is complete, the process moves the block into users space and immediately request another block. This approach will generally provide a speed up compared with the lack of system buffering. The user process can be processing one block of data while the next block is being read in. 

The operating system is able to swap the process out because the input operation is taking place into system memory rather than into user process memory. This technique does, however, complicate the logic in the operating system. 

B)    DOUBLE BUFFER

An improvement over single buffering can be had by assigning to system buffer to the operation. A process now transfer data to  one buffer while the operating system empties or fills the other. 

 It is therefore possible to keep the block oriented device going at fullspeed if . On the other hand, if  double buffering ensures the process will not have to wait for I/O. In either case, an improvement over single buffering is achieved.

 Again, this improvement comes at the cost of increase complexity. For stream oriented input, we again are faced with the two alternative mod of operation. For line-at-a-time I/O, the user process need not be suspended for input or output unless the process runs ahead of the double buffers. 

SPOOLING

Spooling is a way of dealing with dedicated I/O devices in a multiprogramming system.  Instead what is done to create a special process, called a daemon and a special directory, is a spooling directory. Spooling is not only use for printers it is also used in other situation. For example, file transfer over a network often uses a network daemon. 

To send a file somewhere, a user puts it in a network spooling directory. Later on, the network daemon takes it out and transmit it.  This network consists of thousand of machine around the world communicating by dial up telephone lines and many computer network

Memory Management

Relocation

In a multiprogramming system, the available main memory is

generally shared among a number of processes.

Typically it is not possible

for programmer to know in advance which are the programs that will

reside in the memory during the execution time of a program.

In addition

we would like to be able to swap active processes in and out of main

memory to maximize processors usage by providing a large pool of ready

processes to execute.

Each process should be protected against unwanted interference by

other processes, whether accidental or intentional. Thus, programs in

other processes should not be able to reference memory locations in a

process, for reading and writing purposes without permission.

Virtual memory can also work in a multiprogramming system. For example

eight 1M programs can each be allocated a 256K partition in a 2M memory,

which each program operating as though it had its own, private 256K machine.

In fact virtual memory multiprogramming fit together very well. While a

program is waiting for part of itself to be swapped in, it is waiting for I/O and

cannot run so the CPU can be given to another process.

The main problem of contagious allocation is external

fragmentation. This is overcome in the present scheme. Here a process is

allocated the physical memory where ever it is available, and this scheme

is call as paging scheme.

In the basic method physical memory is broken into fix size block

call frame. The logical memory also broken into block of the same size

called pages.

Every address generate by the CPU is divided into parts: a page

number (P) and a page offset (d). The page number p is use as an index

into a page table. The page table contains the base address of each page

lying in physical memory. The base address read from page table is

combining with page offset (d) to generate the physical memory address.

Before we consider ways of dealing with the shortcomings of partitioning,

we must clear up one loose end, which relates to the placement of processes in

memory. When the fix partition scheme is used, we can expect that a process

will always be a sign to the same partition. That is, the partition that is selected

when a new process is loaded will always be used to swapped the process back

into memory after it has been swapped up. When the process is first loaded all

relative memory references in the code are replaced by absolute main memory

addresess determine by the base address of the loaded process.

Now, consider that a process in memory include instructions plus data.

The instructions will contain memory references of the following two types;

some arithmetics and logical instructions.

Addresses of data items, used in load and store instructions and

instructions.Addresses of instructions, used for branching and called