Hello Andrea
Sure you can, just one catch, you will need a copy of a qualifying
media(98,98SE,ME,NT4,W2K)(restore CD's will not work)for and one point
during the install it will have you insert it, this is to prove that you own
a previous version to qualify for and upgrade.
The XP CD comes with all the tools to do a complete delete, partition and
formatting the harddrive.
Disconnect all peripherals except for the Monitor, Mouse and Keyboard before
beginning.
You will need to boot from the CD and after your puter goes through the POST
a message will appear, Press any Key to Boot From CD (press the space bar)
and the install will begin.
When the blue screen appears you will press Enter then F8 to accept the
license and then it will walk you through deleting and formatting. Do the
regular NTFS format not the quick one.
About half way through the install your computer will restart and you will
see the message Press any Key to Boot from CD this time you will do nothing
and it will continue with the install.
http://www3.telus.net/dandemar/cleanxp.htm
After install be sure to visit the MS Windows Update site and download all
the critical updates for your security and safety.
http://v4.windowsupdate.microsoft.com/en/default.asp