The suffix reminds us of the physical limitations of the time. The file was designed to be burned onto a standard 4.7GB DVD. The x86 version was small enough to fit on a CD, but the x64 version required the extra space of a DVD. Merging them both into an AIO pushed the file size to the very edge of a standard DVD’s capacity, making it a tight squeeze that required careful compression.
file to reveal the "Edition Select" menu, granting access to Starter, Home Basic, Home Premium, Professional, and Ultimate editions from one source. Service Pack Integration : Including en-windows-7-aio-sp1-x64-x86-dvd