Windows 7 - Windows 7 x86 and x64 installer package folders and files- Diferrence

I am working on automation project in which we are installing the Windows OS on client machine with the help of different OS packages available on server.

While installing Windows XP/2003 we are checking for the OS installer packages to get the difference between x86 and x64 architectures.
e.g. x86 package contains - I386 folder and PRODSPEC.INI file.
and x64 package contains - I386 folder, PRODSPEC.INI and one additional folder AMD64

Is there any such specific folders or file for Windows 7installer package, by using which we can identify that this is for x86 or for x64?

Thanks,
Jaydeep.

I can't recall anything off the top of my head but the x64 package is almost 1gb larger overall. At least it's that way with disc versions. I remember 2.6 and 3.5gb-ish i think for my Windows 7 x86 and x64 discs.

There may be someone who knows more about it but I figured I'd throw that out there anyways.

I found difference below for Win 7 OS;

x64 package contains : "sysmain32.sdb" which is not present in the x86 package.

Please let me know is this correct or there is something else?