Image Based Install in Vista & Windows PE 2.0

Vista’s installation process is dramatically different to any previous version of Windows: rather than being an ‘installer’, the install DVD is actually a preinstalled copy of Windows that simply gets decompressed onto your PC. So how does it adjust to your hardware? How do you slipstream updates and drivers into it? Can you also ‘preinstall’ your favourite apps into your Vista DVD? Can you build a custom Vista install DVD?

Vista’s “image based install” DVDs contains the Windows Imaging (.WIM) – Windows as images (historically referred to as Sysprep images)file, which is basically operating system folders wrapped up into one image file. This is sort of similar to Linux tarball but involves whole operating system. Rather than being sector-based, as most imaging tools are, WIM is file-based. This means that instead of replicating every single sector of a hard disk, WIM picks up each file and the metadata associated with it (access control lists, short and long file names, and so on) and stores the data in a single file. Windows PE lives in one WIM file on the media (boot.wim), and the installation media exists in another (install.wim)

When users put their DVD in, boot off it and run the setup and it will look to them like they are doing an install, they are really grabbing the install.wim and executing that as an upgrade or clean install depending on what the user wants. Wim is a compressed image with fast compression. There’s also the advantage that it is file-based, not sector-based image, so you can install the image onto your hard drive without overwriting other data.

Vista comes with advanced User State Migration tool called Windows Easy Transfer. Users can take their settings from a previous version of Windows, migrate them off the PC and put them into an installable format for a new PC. So, for example if they wanted to wipe their XP installation completely and start again with Vista, they could take their data off their XP installation with the User State Migration Toolkit and then restore it into Vista once they’ve completed their installation. Windows Easy Transfer can collect settings from Windows 2000 and XP SP2.

One of the great benefits of WIM format, being a file-based format, is separated from the hardware you’re running it on. So you could take an IBM, Dell, Toshiba, whatever you’ve got, build your image up in it, and the way the traditional imaging process works, you can sysprep the machine, drop it and then create the image. That way you can restore the image on multiple platforms. The caveat is that you can’t go from a 32-bit architecture to a 64-bit architecture, but staying inside 32-bit, you are no longer tied to the Hardware Abstraction Layer (HAL) any more. You can now build your golden machine just like before, capture the image and then that image can be deployed widely and as you need to.

Creating customized WIM

A user can mount the install.wim file on the Vista install DVD, mount it using ImageX and put the drivers in themselves through the command line utilities.
You can just load a folder anywhere in the image you like. If there’s something that requires a folder under the system32 directory that is completely unique to some particular hardware, you have the liberty to inject that folder into your WIM.

The other way is that you can use a DriverLoad utility, and that will actually place important things like disk drivers into their required location in the image, so when you are running a setup, it can look through its normal repository for drivers and bang, it’s there, because it has been injected.

When they unmount it, they’d have to burn another DVD of course, but they could have put drivers in there with it mounted into the file system. The drivers are actually injected into the right locations in there.

If you want to build your own golden machine, boot into something like WinPE, and then use ImageX to capture the image, and once you’ve got that WIM image, you can inject drivers into it just like the Microsoft-supplied WIM.

ImageX itself can do a verify on a WIM which is of advantage if you have got the original WIM, a corrupted WIM won’t match up to the original. Note that only Windows PE can boot from a WIM file. You can’t boot all of Windows Vista from a WIM. The WIM is also, as in the case of a CD or DVD, read-only. Thus, you can’t boot from a WIM image of Windows PE and modify any of the files. To make any changes to Windows PE, you must modify the WIM itself.

WinPE 2.0 is along with a boot.wim file will be available in the Windows Automated Installation Kit (829.6 MB DVD ISO Image file)
You can get more details from Windows Automated Installation Kit (WAIK) User’s Guide for Windows Vista

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