So I have two computers, I built one myself and one that i bought, the one bought i don't use anymore as it is broken and am going to throw it away. Both computers run the same windows operating system, and obviously, I have 2 valid windows 7 product keys, one for each PC. Now I am going to build another computer, and was wondering, seeing how I still have the windows 7 installation disc, can I install it on again my new computer that I'm building and then use the product key on the broken PC that I'm going to throw away, would that work, plus I'm pretty sure it's legal (if it does work) as I should of paid for the license when buying the computer.