The Key of Installation of Windows XP is possible locates it for registry?

No it is not possible. Google for magic jellybean key finder. ( http://www.magicaljellybean.com/keyfinder.shtml )

The key is in registry but it's not readable (correct word ?) directly, we need to calculate from regsitry value.

You will find the formula with google.

If you want to try it yourself the cd key is in HKLM\software\microsoft\windows nt\currentversion\digitalproductid

it is reverse base24 encoded in bytes 52 through 66, which when decoded will give you 25 characters of the cd key. Possible key characters are B,C,D,F,G,H,J,K,M,P,Q,R,T,V,W,Z,Y,2,3,4,6,7,8,9.

I was going to suggest trying KeyDecoder from the here but the attachment links are broken. I'll see if I can get it fixed or repost them when I get to work tomorrow.

http://www.dagondesign.com/articles/window...comment-page-5/