Entirely pointless exercise. Changing files or even timestamps changes the hash ... so it won't be an "official ISO" no matter how real you're trying to make it look.
If that was his goal he fails miserably. It appears that the op doesn't understand how hash values work.
Why Fake? It works of course -_- I tried myself some time ago, but never used the -udfver102 switch, so failed I also tried with windows xp professional long time ago.
Thanks prxprx, I can confirm it works, also tried it myself before but never changed the system time zone, so failed then but now it works .
how can this be?I thought the hash is a unique id. But the isos being actually the same and only ei.cfg is different, this explains it.
Relatively unique at least. There is currently no known method to produce a (meaningful) file with a given hash. By exactly reproducing the steps Microsoft takes to build the different versions, you get the exact same result - with the same hash, of course. Since the only differences are the DVD label and the contents of ei.cfg, this is quite easy to accomplish.
Don't call someone an idiot before reading whats been said IDIOT! He said the file would become "official" I said it wouldn't because the other hash's within the ISO would still be WRONG.
If the SHA1 is identical then the iso IS OFFICIAL. ISO hash can't be indentical to the official iso if any individual file even has a 1 byte difference.
The contents of the ISO would have different checksums in areas, you can't modify a file and get the same checksum FACT. Example if i modify ei.cfg from Ultimate to HomePremium its going to have a different hash, therefor when you look into the ISO it will clearly show the file has been tampered with, this meaning its NOT official. If it was so easy to forge checksums don't you think this would be well known and all over the place by now?
I think there are some misunderstanding. If you modify the ei.cfg from Ultimate to HomePremium sure the hash of the former will be different to the latter. But the hash of the latter will be (if i undestood correctly) the same as the original HomePremium made by MS.
Here's the thing... the OP is correct. So long as you change your time to match the original time stamp and time zone of the original file you will not be modifying the timestamp data. What the OP was talking about is, since all the files except the ei.cfg file are the same across all of the editions (of the same x86/x64 version), if you ONLY change the ei.cfg file to a matching file from another edition, you will be able to make the SAME image with the SAME hash. To simplify things.... If you took the Windows 7 Home Basic ISO, replaced the ei.cfg file with the one from Windows 7 Ultimage and saved the ISO --WITH THE SAME TIMESTAMP-- it will have the same SHA1 hash value as the official Ultimate ISO. It's very long winded and time consuming and not very practical / useful for many people, but it's how things are done and informative for those who didn't know this before.
NO ONE IS FORGING ANYTHING. files are simply unpacked, nenecessary changes made to ei.cfg such that it is IDENTICAL to the MS ei.cfg for that edition, and files are finally repacked using the same method and parameters that MS uses. Result=Official MS ISO. Supoose that any file is modified after unpacking, such that it is NOT identical to the MS file, then ISO hash will ALWAYS change.