One of the nice things to come out of Microsoft’s complete overhaul of the Windows installer for Vista and beyond was that it did away with the idea that different variations of Windows needed different discs. Previously each distribution of XP (Home/Pro/MCE) required its own disc, and then each license type (OEM/Retail/VLK) also required its own disc. This lead to an astounding number of disc types, and complete and utter frustration when for users attempting to install Windows and not having the correct disc to go with the key they had.
With Vista’s image based installer, we saw Microsoft consolidate all of this – one disc could contain every distribution of Windows, allowing a user to always be able to install Windows with any Windows disc, regardless of what their key was. This greatly simplified the installation process, resolving one of the most frustrating things about installing Windows XP.
So imagine our surprise when we’re taking a look at our TechNet copies of Windows 7 and find that there’s a different installation disc for each distribution of Windows. With the version of the Windows installer that comes with Win7, there is a new file at /Sources/ei.cfg that tells the Windows installer what OS it should install. Here’s what the file looks like from the ultimate disc:


When the Windows installer sees this file, it becomes keyed to whatever distribution the file specifies. In this case with an Ultimate disc, we cannot install Home Premium or Professional. We have not yet had a chance to test OEM and retail keys since we don’t have both, however it certainly looks like the installer is going to make a distinction there too.
Perhaps the most interesting bit of this is that the installation process itself hasn’t changed – the Windows installer still supports One Disc to Rule Them All operation, and the Windows image that comes with Ultimate for example has absolutely no problem installing lesser versions. In fact if you remove ei.cfg so that the Windows installer is not told to install a specific version, it will revert to One Disc mode. The distinction between discs is entirely trivial, dictated by a single 51 byte configuration file. You can have a One Disc installer, Microsoft just don’t want it to be the default action for some reason.
Now to be fair, this didn’t entirely catch us off-guard. We first saw this file and its functionality with the Win7 Beta, but until now we did not know if this was something that was specific to the testing versions of Win7, or if it was going to be pushed out in to retail with this limitation. Now we know our answer.
The biggest downer though is that this file is fairly tricky to remove. For copies of Windows packed in ISO files or burnt to discs, this requires remastering the ISO/disc in order to maintain its bootability – it’s not possible to just copy the contents to a new file/disc sans ei.cfg and have a One Disc. Building a proper bootable ISO/disc is still more of a dark art than a science. Users looking to install Windows from a USB flash drive will have an easier time – since installers set up on those types of drives are rewritable it’s easy to remove the offending file. Though this may not be the case with officially distributed flash drives should Microsoft go ahead and distribute Win7 that way, as rumors suggest they will.
In any case this is a significantly disappointing action coming from Microsoft. The One Disc returned the sanity to installing Windows, and made having so many distributions more bearable. Now as far as pressed media is concerned, we’re back to the dark ages of Windows XP (I guess Microsoft really was trying to copy everything about XP?). Geeks would be well advised to burn a copy of Windows 7 with One Disc capabilities as soon as they have it – if the experience is anything like Vista then the benefits will quickly make themselves apparent.
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  • 13Gigatons - Wednesday, September 16, 2009 - link

    When asked about this Microsoft said most people would end up installing the wrong version so this file forced them to install the version they actually bought.
  • mrSHEiK124 - Sunday, August 23, 2009 - link

    I can't believe anyone is actually defending Microsoft's decision and calling everyone a pirate.

    When someone with a Dell running Windows XP asks me to reformat their computer, I need a DELL Windows XP CD. When someone with an HP needs a reformat, I need an HP CD. That was ridiculous and annoying.

    It was of very little inconvenience to Microsoft (and EXTREMELY convenient for consumers) to just have the Vista CD "work." I put in a Dell Vista Home Premium CD key, it installs Vista Home Premium OEM, and so on, so forth.

    This is a damn shame, and anyone who thinks otherwise is an idiot.
  • cvt - Saturday, August 15, 2009 - link

    Wow, the arrogence and inexperience of the people leaving comments is bewildering.

    This is terrible, I only fill in IT when the main man is away.
    The combination of 2 or 3 different companies OEM's, VLK and Retail makes XP a nightmare.
    If you don't understand the pain caused by these multiple disks, you are the one that is blind and has an issue.
    Piracy is EASIER than keeping it genuine, unfortunately, companies like to keep it genuine. Fine for Vista, but almost no-one uses it.
    1 disk for all doesn't encourage piracy, quite the opposite, and piracy isn't the right word either, liscenced machine, non-genuine key. Simply to eliminate the nightmares.
    The real world isn't as simple as your 2 computer lifes.
  • Codesmith - Thursday, August 20, 2009 - link

    I keep two install CDs ... Home/PRO.
    I use nlite to setup an unattneded install.
    I use driverpacks to integrate the latest drivers.

    A quick edit to the unattended install file and I have the right CD-KEY, and a bunch of other settings.

    A quick edit to another file and I decide if its OEM, Retail ....

    Finally if its a Royalty OEM that uses SLP volume keys ... well I ignore the key on the sticker, that's not the real key.

    I use the appropriate volume SLP Key ... they are tied to the version of windows not to the manufacturer ...

    I then download the OEMBIOS files for the manufacturer.

    OEM's like Dell get to use the same CD-KEY for all their systems, they also get to skip activation and instead use system locked preactivation.

    SLP compares the encrypted information stored in the OEMBIOS with the BIOS on the motherboard. If you use DELL OEMBIOS on a Dell motherboard it will match and XP will accept the SLP volume key and the system will be automatically activated and remain activated as long as you don't switch motherboards.

    So basically I created a Dell Install Disc but without any of Dell's Crapware.

    Actually you can cheat and just create discs for One OEM then switch out the OEMBIOS files in safe mode.

    Anyway all this is rather hard to figure out and setup, but when you do it you can quickly create a custom install CD that will meet your needs.

    Vista was a step forward with its unified discs.

    Looks like Windows 7 Wants to be a step back. If they wanted to simply things for the typical users but keep the repair geeks happy ... they should have let you override the version choice by pressing an F key or something.

  • Codesmith - Thursday, August 20, 2009 - link

    PS since you are using the same CD Key and same system locked pre activation method as the manufacturer ... it automatically activates and always stays activated .. no calls to Microsoft ever.

    This is far better than a pirated copy for a legitimate machine. You will have to use various hacks to get it activated and to get it to validate. Those hacks will get out of date or be undone by a update.

    Its best to create your own install disc that works just like the manufacturers disc only no crapware.

  • Talys - Thursday, August 13, 2009 - link

    First, reasons for single disc: subscribers to MSDN/Technet or any of the other channels that receive download media from MS have a zillion versions to download.

    Even on a very fast connection, downloading all the various versions in 32 and 64 bit is excruciating. That's Starter, Home, Premium, Pro, Ultimate, Enterprise -- in 32 and 64 bit, or 12 DVD size images. Even if you don't use them all, you'll probably download at least 5 or 6 images.

    Plus, I like to have in my CD wallet that I carry around as few discs as possible.

    That being said, I think a "thank you" is in order to the author for pointing out the "fix" -- at least as it pertains to the retail (non-Enterprise) SKUs. Making a bootable DVD isn't THAT difficult. If you have one of the subscription services from Microsoft, AND you are interested in a single-boot disc, AND you're reading this website, you can surely figure out how to make a bootable DVD. If not, you probably need to find a new job. ;)

    So, anyhow, thank you :)
  • Beerpocalypse - Friday, August 14, 2009 - link

    The thing I hated the most about XP was the fact that you had to call their support line to activate your copy after you reach the max limit of installs with your CD key. They try to get you to spend even more money on top of what you paid by pushing revalidation on you just for the convenience of not having to talk to someone in India on the microsoft hotline for 20 minutes about a stupid serial number. :(
  • LuxZg - Wednesday, August 12, 2009 - link

    There is more to this than just this ei.cfg file.

    I have Ultimate (retail) and Enterprise (OEM) ISO images on my disc, directly from MSDN. Interesting enough, they are 100MB different in size, even though both are 64bit. How come?


    ei.cfg containing this


    ei.cfg contains this

    next up we have install.wim file, which is 2.760.348.780 in Enterprise, while it's 2.860.840.523 in Ultimate ISO image.

    Than we have one huge and obvious difference - Ultimate has 4 install_*.clg files for Home Basic, Premium, Professional, and Ultimate.
    Enterprise ISO contains only ONE file -> "install_Windows 7 ENTERPRISE.clg"

    And finally, we have product.ini in both ISO files, but they are also slightly different in size. Difference is in the last line which is...

    in Ultimate:

    in Enterprise

    So while deleting ei.cfg maybe "unlocks" DVD for using it with Basic/Premium/Pro/Ultimate, it's possible that it can't be used for Enterprise installs.

    Also it and seems that Starter is missing as well, but ofcourse I've got 64bit ISOs (and Starter is 32bit only), so I don't know if 32bit ISOs have same "catch".

    Also, if you go to MSDN you'll notice separate ISO images for EVERY Win7 edition.
    64 bit versions are all 3,075.30 (MB), except Ent. which is 2,976.62 (MB).
    Similary, 32bit Ent edition is 2,289.20 (MB), while all others are 2,385.99 (MB) - including Starter.

    I'm not downloading them all just to see if they all follow the same routine, but according to all this, I'd say you can make a "One disc" for all versions EXCEPT Enterprise - that one would have to be separate.
    Why is this different I don't know, and I'm not investigating further. But while several differences I've mentioned are easy to explain (small text/EULA differences and such), I can't think of a good enough reason for Enterprise install.wim file being that much smaller than "all others" install.wim file.. I'll leave further investigation to you folks :)


    P.S. And why does products.ini seem to contain product keys for dozens of MS software listed inside is beyond me :D
  • dagamer34 - Wednesday, August 12, 2009 - link

    I'm pretty sure it's designed to prevent people from installing higher versions when their key is for something lower. There isn't a way to "downgrade" an install of Windows 7 Ultimate to say Professional or Home Premium.
  • MeStinkBAD - Saturday, August 15, 2009 - link

    Why does Windows have separate installs to begin with? It does not benefit anyone. Period. Oh sure a home user may not use it the same way an enterprise user would. But that does not explain why separate versions of the exact same operating system need to be sold w/ different user agreements.

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