i have genuine windows7 pro coa stickers that never been used previously.
for realize that windows activation key is genuine and unused you have two ways:
1.for verification of type of Windows Activation Key: download this program that called "Volume Activation Management Tool 2.0" from mcrosoft
and enter your activation key.then you can see your key type and windows version.
like this :
2.to realize that windows activation key genuine and unused: you should ask microsoft online chat for verification.
like this screenshot:
PM me please, if you have any question or add my skype: xychrizzy