Possible same xp activation key on two machines?

[gizmo1990]

I've reformatted and reinstalled xp pro on my sisters laptop and when I went online to activate it I got asked to enter my product key again. This has never happened before, so I did and it failed...

Hmm I couldn't think what was wrong until I thought maybe I somehow got her installation cd mixed up with my seperate copy too? So I entered what, up till now, I thought was my xp key and lo it worked!

Now the question this asks is, am I running the same key on my machine?

Is there anyway to find this out? Or would the very fact that I was able to register the key mean that I could only be running my sisters key cos MS's database wouldn't allow the same key to be registered and running at the same time!?

Any help appreciated.

 

[gizmo1990]

Thanks for that guys, thats a very useful little program.

I've run it and I knew I wasn't going nuts, I'm running my key on my sisters laptop now, which means I'm running 2 machines off one code!

Now that raises the question is anything going to happen to either machine? does anyone here know if xp occasionally sends off its key to ms?

I'm very worried that my pc's gonna bork or something!?