Question about Restore Discs and Windows Activation

I have 2 identical Asus laptops and when I made the restore disks, I didn't make which set was for which laptop. I just did a full restore on both units and windows says it's activated. How can I check which key is on which one? My worry is both may either have the opposite machines key, or worse yet they may have the same key. Does it really matter? I am selling them now and do not want to put the new owner in a bad position down the road when during a windows update it says thier key is already in use. If the new owners do not make thier own backup discs will they be screwed down the road?

I am tempted to stay up late and waste another 12 DVDs just to make a new set for each so that I know all is well.

*Edit*
I guess it won't do any good to make the new restore disks since I already restored them both and don't know which one is which or if they are from the same discs. I made 2 copies of one unit and one from the other when I got them, so having 3 sets is part of what messed me up. There is a good chance both of them have the same restore done on them.

I also used a keyfinder but it said they both have the same key, and neither matched what was on the bottom of the unit. Could it have something to do with the way the OEM license works?

 

take three deep breaths......

 

Lol, thanks. It was a late one last night and I probably had too much caffiene in me. I am mailing one as soon as I get payment, so I was hoping to find out before it's too late to do anything.