I built my first system with the help of the members of Toms Hardware. My computer is tied to windows 7 based on the software that I need to run. I bought, and am running a copy of windows 7 home oem from a local computer company. I had a weekend of rebooting to finally get all of the drivers I needed working. I now want to upgrade to ultimate to unlock higher ram capabilities, but anytime upgrade is no longer an option. I dread a clean install from my past experience with getting the various drivers to work. Is there a legit way to upgrade without a clean install?