Want to reinstall your Windows XP operating system, but don't have the installation disc? If so, you will need the product key.
Steps
Part 1 of 3: Prepare

Step 1. Back up your data
It is highly likely that you will lose all of your data during the reinstallation process. Backing them up will therefore allow you to restore them at any time.
After your data is backed up, you need to put the backup file in an external location like a disk or USB stick

Step 2. Find your product key
This is a 25 character code. It is usually found either on a sticker on the bottom of laptops, on the back of the CPU (desktop computers) or in the box of Windows XP.
It is possible to use ProduKey to obtain the product key if you cannot find the sticker

Step 3. Click on Start
It's the green button at the bottom left of your screen.

Step 4. Click on My Computer
This is the icon in the form of a monitor located at the top right of the window To start up. The folder Workplace will then open.

Step 5. Enable visibility of hidden folders and files
For that:
- click on the tab Tools which is located at the top left of the window;
- click on Folders option … in the drop-down menu;
- click on the tab Display;
- tick Show Hidden Files and Folders;
- click on To apply, then on OK.

Step 6. Double click on Local Disk
It can be found under the section Hard disk drives in the file Workplace.
- Instead, double-click on the disc (VS:) if there are multiple local disks.

Step 7. Double click on the Windows folder
This action will open the file.

Step 8. Double click on the i836 folder
You might have to scroll down to see it.

Step 9. Find the winnt32.exe file and double click on it
The Windows XP installation process will then be launched.

Step 10. Wait for the settings window to appear
This can take a few minutes - it all depends on how fast your computer is and what programs were open before you double-clicked the winnt32.exe file.
Part 2 of 3: format your computer

Step 1. On the blue screen, press Enter
The installation will then be launched.

Step 2. Press the I Agree button
At the bottom of the screen you will see to the left of this option another button (for example F8). To continue with the installation, press this button to agree to Microsoft's terms of service.

Step 3. Press the Do Not Repair button
You will see it at the bottom of the screen. Usually this is the Esc key.

Step 4. Remove your current installation
Using the directional buttons, select the option NTFS hard drive, then press the To delete (usually D) at the bottom of the screen.

Step 5. When prompted, press Enter
This will tell Windows that you want to remove the selected installation.

Step 6. When prompted, press L
In doing so, the hard drive will then be erased and the installation menu will appear.

Step 7. Press Enter after selecting Unpartitioned space.
Your hard drive will then be selected as the mount point.

Step 8. Format your hard drive
Select Format partition using NTFS file system and then press Enter. Thus, the hard drive will be configured to start the installation process. It could take a few minutes or even an hour: it all depends on the capacity of your hard drive.
- You could also choose the formatting option here Fast. On the other hand, your hard drive could be badly formatted.

Step 9. Wait for your machine to restart
It will restart in the user choice configuration window, once the formatting is complete. Be careful not to press any key until setup is complete.
Part 3 of 3: Configure Windows XP

Step 1. Click Next
It's the button at the bottom right of the window.
- It is also possible to click on the button Personalize… located to the right of the section Regional and linguistic options. You can choose a different language or geographic area.

Step 2. Enter your name and click Next
Enter your name in the field provided.
- In the game Organization, it is possible to add the name of your company.

Step 3. Enter your product key, then click Next
Enter the 25 character key you found earlier in the boxes provided.

Step 4. Add a password and click Next
At the bottom of the window, in the fields Administrator password and confirm password, enter the password of your choice.
It is also possible to change the name of your PC in the text field located at the top of the window

Step 5. Set a time zone and date and click Next
Select the current date after clicking on the drop-down menu, then do the same for the zones Time zone and Time.

Step 6. Choose the Typical Settings box and click Next
The default settings will be used during the installation of Windows XP.

Step 7. Choose the No box
It is located in the upper part of the window. Check the box Yes if your computer is in a workgroup, then enter the workgroup address in the text field.

Step 8. Click Next
This will complete the installation setup process, otherwise Windows XP will resume installation. You may have to wait about 30 minutes before the end of the operation.