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.
By bundling both x64 and x86 architectures, this single DVD allows you to install any edition of Windows 7 on any compatible PC from a single USB drive or disc. en-windows-7-aio-sp1-x64-x86-dvd