Operating system is a computer program that controls the components of a computer system and facilitates applications and data. Some of the operating systems available in the market today are: Window 98, Windows Me, Windows 2000, Windows XP, Linux, UNIX, and MacOS.
We are only going to discuss installing Windows XP for this tutorial since we are only focusing Personal Computer. Windows XP is the latest Microsoft Operating system widely available.

To format your hard drive complete and install fresh copy of windows xp on your computer or install Windows XP to a new hard disk, you have to run Windows XP from bootable CD. To do this:

1. Turn off your computer.
2. Insert the Windows XP bootable CD. If you do not have a bootable CD, download the WinXP 6-floppy disk from BootDisk.com to startup the installation process.
3. Turn on your computer and press any key when it asks "Press any key to boot from CD". Your computer should run from the CD inserted and start Windows XP installation wizard. If your computer jumps to the installed operating system or does not read from the CD. In that case, set up the boot sequence in the BIOS. Your computer will tell you how to access to the BIOS when you turn on. Some computers use DELL key or F2 key to access the BIOS. Your boot sequency should be: A drive first, CD second, hard drive third.
4. Read the End-User License Agreement, and then press F8.
5. At the Welcome to Setup screen, press ENTER to start Windows XP Setup.
6. Follow the instructions on the screen to select and format a partition where you want to install Windows XP.
   
7. Follow the instructions on the screen to complete Windows XP Setup.
8. Once the installation is finished, your computer will automatically restart.

Note: If you notice improper graphic display or hardware device such as network card, sound card, modem, etc malfunctioning. The driver of that component is not installed. Find your mother board CD or expansion card CDs and install them.

1. Start up your computer and run the currently installed Windows.
2. Insert the Windows XP CD into your CD drive or DVD drive.
3. CD should automatically run and launch Windows XP start up menu..
4. Click the "Install Windows XP" once the setup menu pops up.
5. Welcome to Windows XP Setup popup window will appear. Make sure you select Upgrade from the list. If you select New Installation, that will install fresh copy of Windows XP on your hard drive. Click Next.
6. Read the End-User License Agreement, and click the "I accept this agreement" button.
7. Enter the registration code that come with Windows XP package and click next.
8. Keep clicking next. Enter if widows ask your area cod for the modem setting. Choose your Time Zone "Eg: Eastern Time". If you do not select correct Time Zone, your computer time might be wrong.
9. Enter the registration code that come with Windows XP package and click next.
10. Enter your name once asked by the windows setup.
11. Your computer should restart when the setup completes the installation.
12. If your version of Windows XP is Pro Edition with Server Pack 2. Firewall option will pop up. Select the option that says "Help Me Protect My Computer" to activate windows firewall.

Note: If you notice improper graphic display or hardware device such as network card, sound card, modem, etc malfunctioning. The driver of that component is not installed. Find your mother board CD or expansion card CDs and install them.

To update Windows XP over the Internet through the Internet Explore;
1. Connect to the Internet.
2. Open your browser.
3. Select Tools, and click on Update Windows.
4. Wait while the Microsoft determines your update requirement.
5. You will get the options "Custom Install" and "Express Install".
6. We recommend that you choose "Express Install". Express install will select all the updates you need. Custom install is for to select which updates to install and which update not to install.
7. Restart your computer once the updating finishes.