During the 2009-2010 school year, I purchased Windows 7 Pro through school. I used it for a while, but uninstalled it when I upgraded that system and put Linux on it. So now I have a windows 7 key and license floating in limbo. Not installed on any device. And I lost the key ages ago. Now that windows 10 is out, my gaming rig could use the upgrade. Is there any way I can contact microsoft and get this key back, and install/activate it so I can upgrade to windows 10?