Hi, I am having a problem with my Windows 7 activation. I have installed Windows 7 on my computer and then due to some reason the blue screen error was appearing on my computer, so to solve it I move back to the Windows vista. Before moving to Vista, I have activated the Windows 7, So, now I want to deactivate the Windows 7, so it can be used by friend of me by again activating. So, is there any way to do this. If yes then please help me to achieve that.