In a November 21 blog post written by Christa St. Pierre of Windows Setup and Deployment team talks about the improved setup experience of Windows 8.
Pierre writes "With Windows 8 setup we have greatly improved both speed and ease of use, while still retaining all of the advanced setup functionality that many customers will demand. We have integrated what was once many separate steps for people to perform when preparing and starting their setup into a streamlined user experience, with a fast and reliable setup engine under the hood."
Windows 8 setup has been designed for online delivery, in addition to the local delivery from a DVD or USB drive. The two main areas of improvement for Windows 8 are constructing optimized download packages, and making sure that downloading is flexible and resilient.
Pierre said in order to optimize for download in Windows 8, "we take the required subset of files for the specific version of Windows being downloaded. After eliminating duplicates and compressing resources, the single-file size is 2.10GB (as compared to 2.32GB), a savings of 9.5%. After this optimized package is created we compress it using an improved compression algorithm specifically for Windows 8 setup, which provides an additional 28% savings. In this example (using the Windows 7 x86 ISO) the size of the download would be reduced from 2.32GB to 1.51GB."
Adding, he says the download manager included in Windows 8 setup downloads the optimized package containing the new OS and reconstructs the layout required to run through the install process, without leaving duplicate files on the system. It verifies the bits that're downloaded in 10MB increments. If verification fails for a particular increment, the download manager has the ability to re-request only that specific block of data without having to restart the entire download."
He notes, that in Windows 8 during upgrade; we just move the following folders into Windows.old when the PC is offline: 'Windows, Program files, Program files (x86), Users
Program data," means that during the "apply" phase of upgrade (once we are running in Windows 8), everything we need to preserve can be extracted from the Windows.old folder (as we touch no other folders during the upgrade), eliminating the need for a gather phase."
Also, a new feature is added in Windows 8 that automatically deletes Windows.old folder 4 weeks after a successful install, so you don't have to worry about removing it.
Windows 8 also bring advanced setup options that will make it easy for you to customize a bootable USB drive (that you can create as part of our download experience) and automate your installation. For full details about all of the configurations that are possible, check out the Windows 8 ADK (for MSDN subscribers only), and other user can check out the Best Practices for Authoring Answer Files article on TechNet.
Pierre also explains of "Key injection" with "unattend" settings. The specific setting that you will need to configure to do this is the ProductKey setting.
Here's a sample:
You can also configure "unattend" to automatically configure the system for booting multiple operating systems. "You could do this all manually in the Advanced Setup GUI and BCD configuration, but why do that when you can script it? Using the DiskID setting you can create and modify partitions. You can then specify the PartitionID setting to install to a specific partition--one that is different from an existing OS partition," explained Pierre.
Here's a sample to install to a specific partition:
Z:\sources\install.wim 0 1 OnError false
"Once you've your answer file configured to your liking you can copy it to the root of your USB media. (Remember, if you use setup from the web, you can still create a bootable USB drive or save to an ISO.) You can also include the file at the root of the DVD media where you burned the ISO, if you chose that route instead. Even cooler, the unattend file doesn't even have to be on the installation media. In fact you can place the unattend file at the root of a USB flash drive, plug in the flash drive before starting setup, and setup will automatically find it and use it," added Pierre.
Here's a video demonstrating an advanced setup from a USB flash drive: