In place upgrade ?

I had laptop A that came with win7 home premium and I used an in place upgrade key for win7 pro. I used the factory restore software and the restore partition to return it to it's original home premium set up so I could sell it. I now have laptop B and I am wondering if I can use the same pro key to upgrade the new machine? I know you could do that with retail versions of windows as long as it was only on one machine at a time but I'm not sure about the in place upgrades. Thanks

Yes, you can reuse the pro key. Upgrade license is retail so it can be moved to laptop B since you have removed it on laptop A.

Thanks Bill,
I kind of figured it would be ok, I just wanted to make sure before I went through the process.

It is an Upgrade version, whether you do an in-place Upgrade or Custom clean install Upgrade. There is no difference in its status.