Discussion in 'Windows 7' started by prxprx, Aug 12, 2009.
Yes, you will be able to select all versions except Enterprise.
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i would like to change only from Retail to OEM
and i would like to do this only for the german Version
so here is my question:
The change of the time zone seems to be important - but what timezone had to be in the German Version of the ISO File?
By the way - the point is not to get the same hash of the source Iso but to get the same Hash of the originaly aimed iso
Thats what the Thread Starter only said is the MS himself only changes it in this way and so the original ISo will be indentical.
The source of all that is the MSDN Ultra 32bit Version
you handle it in this manner described in the start thread and change only to HomePremium
than the sha1 of the changed resulting iso is the same with the Original HomePremium Iso from MS !!
Just don't see the reason to do that. Removing ei.cfg yes, is better as it let you choose what you want to install at the install time.
Hashes of windows 7 files are not changed! Also changing a file timestamp does not change its hash. This because the hash of a file depends only on its contents, not on timestamp! Timestamps are information managed by an operating system on the file system of a disc (hard disk, CD, DVD, USB drive, etc.) where files are stored.
We are talking about the hashes of the .iso file in this thread. An iso image is a sector by sector description of the data of a cd/dvd. So, a .iso image is a FILE representing a cd/dvd file system (it's UDF ver. 1.02 in m$ windows 7 dvd's). It then has information about files, folders, timestamps that will be part of the disc. Also boot sector, producer, file system, etc. are stored.
The key point is that files, folders and their timestamps are part of the CONTENT of the .iso file! So, they affect the .iso file hashes!!! That's why is necessary mantain the same timestamp of the original image.
Exactly. If the iso image has the right hash, then the files have the right hash, too.
I forgot to explain this point. Thanks twiz.
If you read further on I caught onto what was going on. I presumed it'd be adding other files that are not already on the disk to start with, thats what I get for not fully reading everything and paying attention to the command used to output everything with the same timestamp. Again my apologies.
Unlike Vista, Windows 7 NEEDS the ei.cfg file during installation. If you remove that file Setup will abort with an error message.
Before anybody starts doubting this, let me tell you that, I have already verified this (fortunately with VirtualPC).
But when I tried to convert my Ultimate .iso to Professional (to give to a friend) the hash generated changed/didn't matched with the official value. Nevertheless it worked OK (again on my VirtualPC). My friend has yet to install the Professional version as his DVD drive is having some problem.
Anyway, why is it necessary to maintain/generate the same hash value as the official values. During installation does setup checks and compares the official hash values to detect untouched .iso images?? Else I can simply download any one version of Windows 7 (most of us already have the official untouched Ultimate version), change the ei.cfg file as needed, save the new .iso and get a new version/edition!!! Why do I have to care about time stamps, hash values etc??
Also since this technique can NOT create the Enterprise version/edition of Windows 7, do I have to download it separately??
The idea about PPF-O-Matic is interesting. Any developments??
I have installed Windows 7 many many times without a ei.cfg. And many others have done it too.
I agree with VelleX, I have also installed Win 7 on a 'Real' PC without the ei.cfg and have never seen setup abort.
Nice thread, this is why many people choose to join technet and not download from net for the os isos.
I know the process gone though in this thread, and understand you cannot do this and that. But just shows you that you cannot fully trust isos from other sources than ms.
Who is to know if this cannot be further hacked.
This thread should be a sticky, if for nothing more than hash details and how they hashes of files are made.
Your completely missing the point: hash values, for all intensive purposes, CANNOT be faked.
Does anybody know how to make an official m$ iso with language pack?
Already verified by myself that works. Installed Win7 HomePremium from the Ultimate ISO where I've removed the ei.cfg by myself. If you have some error probably the ISO creation and/or the burning process were bad. (I've made the installation from a bootable usb pendrive)
No i understand what the process that goes into them.
If this system works then there is no true hash value.
If you add files to the iso. eg. a loader the sha-1 hash changes doesn't matter if you adjust the timestamps. I mean SHA-1 is 160Bit hash which means 2^160 possibilities
So very wrong.
Clearly you don't understand.
This system works because you're building the image THE SAME EXACT WAY MICROSOFT DOES USING THE SAME EXACT FILES.
In fact it ONLY works because you're building the image THE SAME EXACT WAY MICROSOFT DOES USING THE SAME EXACT FILES.
If you changed ANYTHING... add a single space to one of the files that doesn't exist, remove a space, -ANYTHING AT ALL- that is not a 100% match to the official Microsoft one... you'll end up with a different CRC/MD5/SHA-1
The reason the CRC/MD5/SHA-1 of an ISO will match the TechNet CRC/MD5/SHA-1 is because they are EXACTLY THE SAME.