Am I correct in my belief that Windows 7 Professional Upgrade (when released) CANNOT be installed in 64 bit version on a 64 bit machine if the copy of XP already on the machine is 32 bit? Are there no work-arounds? Thanks Dave

You can install either Windows 7 32-bit or 64-bit on a PC running Windows XP. Since no version of Windows 7 can actually upgrade over an existing Windows XP installation, you will have to perform a "custom installation" which is essentially a "clean install". Please see the following which also applies to Windows 7: Installation choices for 64-bit consumer versions of Windows VistaCarey Frisch