Since I purchased an OEM version of windows 7 a few years ago I have had to increase the size of my windows partition twice. The first time I did it the original program would not work so I bought a Key online.. It worked, however after some time went buy I still did not make my windows petition big enough and had to repartition again. You have to reinstall windows, unless I just did not do it right. It doesn't matter at this point, so after some months I get the dreaded you copy of windows is invalid. back screen garbage. Now I have to resolve this or just live with it.. How do I go about getting a copy of windows 7 64 bit, where if I decide to install it again the Key will work on boot camp? What ever key they told me was not good enough for my needs I guess.