Relax, Gabe Newell. If you buy a new Windows 8 Pro PC and discover that you really do detest the OS that much, you may be able to switch back to an older version -- either Windows 7 or Vista, but not near-death XP -- under the same OEM license. Will many folks want to do that? Probably not, and in case these so-called downgrade rights are actually only helpful in specific circumstances and generally don't come wi
