How about a W7 update from XP or better to get an OEM of 32 bit professsional?
Hey Ed, there is no direct update from XP to Win 7 (different architecture), it has to be a clean install. However, you can select a different installation path via 'Advanced Settings' to clean install Win 7 on different drive/partition to XP, thus leaving it intact and operable should you ever need it. Also, an OEM version, which you don't need a previous version to qualify, may actually cost you less than an uprade version.
Thing is with that, though, an OEM is either or 32 bit, 64 bit... not both. Meaning, if you plan to build a new machine later, you might want to wait to purchase an OEM copy of Win 7 until then, if you'd rather run 64 bit, that is.