Which copy of Windows?

[Jerrymc3]

I have 5 computers with 5 copies of Windows7 installed on them. If I need to reinstall Windows on one of them how can I tell which copy of Windows belongs to which computer?

 

[clarkjd]

Go here:
https://www.piriform.com/speccy
Download and install Speccy. run it, look under Operating System, and it will display the key used to activate Windows on that machine. match that with your copies of windows.