Hi all... several months back I did a build and installed Win7(64) as my OS. (a Gigable ud5 board, with an i5, and an ssd). A couple months later, I bought a second copy of this OS to install on another system. BUT... as it turned out the other system didn't need it. I was able to recover with OEM recovery disks. BUT, meanwhile I had opened the new Win7 dvd packet. Then, I set it aside. Now, I am trying to determine which copy is in use on my system, and which is still available for use on another system. Any quick easy way of doing this? Thanks.