Windows 7: Windows 7 Ultimate 32bit Filenames

Hi, on the leaked versions of the official MSDN ISO images the filename is '7600.16385.090713-1255_x64fre_client_en-us_Retail_Ultimate-GRMCULXFRER_EN_DVD.iso' whereas the MSDN filename is 'en_windows_7_ultimate_x86_dvd_x15-65921.iso'. Why are they different, and also where did the former filename appear from?

As long as the SHA1 hashes match then it don't matter what it's named. Although, I'm not sure why the build differs from what was leaked as the RTM 3 weeks ago. Not really sure about x32, though since I use x64.

Thats true, but just out of interest, does anyone know where the former filename appeared from? Is it from an official Microsoft source? According to mydigitallife they say this: 'Some channel may distribute the ISO files in other name', but im wondering where it oringally originated from...

One name is the name generated by the build lab:
7600.16385.090713-1255_x64fre_client_en-us_Retail_Ultimate-GRMCULXFRER_EN_DVD.iso

7600: build #
16385 (0x4001): QFE #
090713-1255: build tag
x64: compiled for x86-64
fre: "free" build (vs. "checked" builds that have compiler optimizations turned off and debugging information left in; checked builds of Windows are typically used only by the Windows Team or by MSDN subscribers who need to do OS-level debugging; TechNet does not get checked builds)
client: component identifier (vs. WDK, SDK, etc.)
Retail_Ultimate: edition
GRMCULXFRER_EN: disc label
DVD: disc type (duh!)

That's the "original" name, and that's the sort of name that gets used in most official non-retail distribution channels (e.g., Connect), and, as I understand it, that's the name that all the employees see. Also, for things like the WDK, SDK, and WAIK, when you download it from the official download center, they will have similar "build lab" file names.

The exception to all this is MSDN/Expression/TechNet, where they use what amounts to a packaging name. The "X15-65921" is actually a part number that gets printed on the pressed discs and, as I understand it, is used for things like inventory and ordering.