I have a DELL Laptop that came with WIN XP preinstalled. Later, I got a WIN 7 copy from a friend and installed. WIN 7 automatic updates are giving trouble. The authentication key (product key) on the sticker on the back of the laptop is partially damaged. I can locate 10 of the 20 letters/digits. Is there anyway, that enables me to get back my original authentication key by which I can go go back to WIN XP (that was pre-installed with laptop) and avoid the windows updates problems.
If you have the original Dell install media for XP, then there shouldn't be a need to enter in the product key. Barring that, your only real hope would be to contact Dell support and/or Microsoft's activation hotline.