Windows 8's retail release is fast approaching. Unless the new Metro user interface gives you a rash, you might be thinking of upgrading—and an in-place upgrade would be the least painful way to do that. Well, ZDNet has gathered some helpful information about which past editions of Windows will support in-place upgrades to the new OS. The information isn't strictly official, but it should be legit. It reportedly originates from "select" Microsoft partners who were briefed by the software giant earlier this month.
Generally speaking, ZDNet says doing a full upgrade from Windows 7 to Windows 8 won't pose a problem—but there will be two small caveats. Upgrading to a version of Windows 8 based on a different architecture won't be possible (so, no upgrading from Win7 x86 to Win8 x64), and users of Windows 7 Professional, Ultimate, or Enterprise won't be able to upgrade to the vanilla version of Windows 8.
What about Windows XP and Vista? A full upgrade from Vista to Windows 8 will be possible, but only if you have Service Pack 1 or later installed. Upgrading from Windows XP or pre-SP1 versions of Vista will cause your settings and customizations to be wiped; only your personal files will survive. ZDNet says cross-archiecture upgrades will be a no-no, just like with Windows 7, but it doesn't clarify whether cross-edition upgrades will also be verboten. (In other words, I'm not sure whether you'll be able to hop from Vista Pro or Ultimate to the non-Pro version of Windows 8. I'm guessing not, though.)
Of course, in-place upgrades are but one way to install a new operating system. No matter what version of Windows you're running, you should be able to back up your files to a safe location and do a clean Windows 8 install. I might go that route myself, actually. The Windows 7 installation on my desktop PC dates back to August 2009 and is getting slightly crusty.