Q. Do I need to download all the different versions of Windows 7 from MSDN?

A. MSDN has a different ISO for each version of Windows 7 (e.g. Ultimate, Professional, Starter) but they're all the same ISO. The only difference is that there's a file (ei.cfg) in the sources folder that tells the setup routine which image to select. You could, therefore, open the ISO, remove this file, and save the ISO. You'd be prompted for which version of Windows 7 you want to install, as shown here. You do, however, still need to download the x64 and x86 versions of Windows 7 if you want both the 32-bit and 64-bit versions.

You could also create multiple ISOs and modify the content of ei.cfg. The format is

[EditionID][Channel]Retail[VL]0

So just change to Ultimate, Professional, HomePremium, HomeBasic, or Starter. See this Microsoft site for more information on ei.cfg

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