Windows Vista x64 Support, Migration, 1

If your organisation is considering migrating to the x64 side of the server and processor pool, then these few pointers might be of use. Microsoft provides a version of the Windows Pre-installation Environment (Windows PE) specifically for the x64 architecture. However, since x86 and x64 systems have hardware parity, you could also use the 32-bit version of the PE to deploy a 64-bit system. While using unattend.xml, though, Windows PE needs to be architecturespecific: as winnt32.exe must run under the same architecture it is deploying. Since Windows PE does not have a 32-bit compatibility layer, and winnt32.exe under x64 is a 64-bit application, 32-bit Windows requires 32-bit Windows PE. The same applies for 64-bit versions of Windows, which require 64-bit Windows PE.

If you are thinking of upgrading your OS from a 32-bit path to 64-bit, things get a bit difficult. You cannot upgrade from any version of Windows XP (x86 or x64) to Windows Vista x64. Windows Vista on x64 systems is a clean-installation-only product. You might thus consider a migration to 64 only under a fresh hardware upgrade.