As with every new Windows version, Microsoft is streamlining the Windows setup process, writes Christa St. Pierre on the Building Windows 8 Blog. The biggest change is the new online installer for Windows 8, which can download the installation media directly from Microsoft's servers and install the operating system without so much as bothering the user for a product key (for upgrade installs). Those wanting to do clean or advanced installs will be given the option to copy the installation files to a DVD or USB drive. 

Windows 8 will further streamline the upgrade process by folding both Windows Upgrade Advisor, which scans your computer for hardware and software and checks its compatibility with Windows 8, and Windows Easy Transfer, which allows easy and granular controls for backing up and restoring files and settings, into the Windows installer rather than keeping them as separate applications. The new installer will be able to upgrade OSes as old as Windows XP (which will preserve only user data), though users upgrading from Windows Vista or Windows 7 will also be given the option to preserve Windows settings and applications, respectively.

Lastly, Microsoft has made changes to how the upgrade install works with user files to reduce the amount of time taken. Previous installers would move user files to a temporary location, install the OS, and then move them back. The Windows 8 installer reduces the number of file moves, and uses "hard links" to files to change their location in the file structure without physically moving the data around. Microsoft's graph below shows a drastic reduction in time for an upgrade install under Windows 8.

For those of you who prefer boxed software, Microsoft will continue to sell boxed copies of Windows on DVD. Users who initiate the install by booting from a DVD or USB drive will continue to see more advanced options for performing clean installs and partitioning disks. Enterprise administrators and power users who need more customization options can continue to use Microsoft suite of deployment tools (now called the Windows Assessment and Deployment Kit, or ADK).

For more details, check out the post at the Building Windows 8 Blog.

Source: Building Windows 8 Blog