...CD flip book case, and that is when you realize that you have lost the product key which was provided as a little yellow sticker when you bought Windows XP. Then you panic. Well, guess what? Hope is not all lost, it is possible to locate your Product Key using nothing more than your Windows XP Installation CD.
To start, you will need access to a working computer.
Stick in your Windows XP Installation CD, then, when the XP Install Splash Screen pops up, click Exit.
Then Click Start, then My Computer and find your CD Drive (mine is Drive I), right click on it and select Search
Then type unattend.txt then click Search
It will find the unattend.txt file and report that it is located in your main drive, don't be misled, this is the right file and it is on the CD.
Open the unattend.txt and in it you will find your Product Key.
Write down the Product Key, now you have the key and can install XP.