Need Help With Windows Authenticity Sticker!

Hey guys.
First of all I would like to say hi to everyone on these forums. I am brand new here, though been following some discussions, checking out software etc, but never posted on here. So please if my question looks/sounds stupid just try to take it easy on me.
So, im one of those guys who everyone turns to whenever they have any kind of PC issues. And most of the time its after the fact when their PC is totally screwed up. Because I am no PC guru I tend to take the easiest route for me which is reformatting the whole thing and installing a fresh copy of windows (XP or 7). But because I use same copy of windows (XP home edition purchased at retail store) I always have to call in and activate it by phone and lie about how many computers this copy of XP is on. I don’t fix PC’s for profit so no worries there, kinda family/friends deal.
So my question is, how can I utilize the code from Windows Authenticity Sticker which is usually attached to the computer I fix???????? And use that code when I install fresh copy of windows???
Thanks in advance,
RJ

 

OK, how about builders license? Is that same thing as OEM (Dell, HP, Acer....) or each manufacturer has their own version of windows? And lastly if each company has their own version of windows do they differentiate lets say between different model computers or i could use same windows xp for a tower and a laptop of same company...?

 

Still need help!

 

Came across this post. Not sure if it would work in your case though.

 

You might want to check this blog and comments.