I am thoroughly confused as to which copies of win 7 i need. I have a new build desktop running the rc copy of 7, 2 laptops and a netbook also running the rc and a server which all my computers are connected to. I need to know what i need specifically for the new build which has run the rc copy from the outset and the netbook which came with ubunto. I'm pretty sure i can go back to Vista and use the upgrade for the 2 laptops but can i use the os copy for the new build even though it already has an operating system on it? I would appreciate any advice.