: Indicates that the package likely includes both 32-bit (x86) and 64-bit (x64) versions of Windows 7 Professional.
: The "Duo" designation signifies that the ISO contains both 32-bit (x86) and 64-bit (x64) versions of the operating system. This allows a single installation medium to be used for both legacy hardware and modern systems. Windows 7 Pro Duo SP1 v2 Orion -MULTI-