"I want to format and erase all the hard disc, except the Window XP"

 

It's all or nothing. If you format or erase the disk, everything is gone and you will have to reinstall Windows XP from the XP Installation CD.

Thank you very much Rebel 9 your answer is clear, two more questions:

 

1) ¿Which command to erase the entire disk?.

2) I understood that after erase it will be enough to restart it to insert the " Microsoft Windows XP Professional Service Pack 2"

 

Best

When you boot from the XP installation CD, you will be given the option to format (which will erase everything) your disk. To boot from the CD, insert the CD into your drive. Then, start the computer and tap F12 as the computer is booting. This will bring you to a boot menu. Select your CD drive, and go from there.