Metro-style user interface
Windows 8 features an extensively redesigned "Metro-style" user interface, optimized for touchscreens as well as mice and keyboards. A new "Start screen", similar to the one in Windows Phone 7, includes live application tiles. The start screen replaces the Start menu, being triggered by the Windows key and Start button, and is also the first screen shown on start up. The user can go to the regular desktop, which is treated as a Metro app with its own "Desktop" tile on the Start screen. Starting a traditional desktop-based application also switches to the desktop. The Start screen also displays the user's name and picture.
Metro applications run in full-screen, or two can be displayed on higher resolutions by snapping one to the side of the screen.
Windows 8 features a new login/lock screen that shows the date and time and notifications, along with a customizable background.
New logon methodsPIN
Instead of typing a password, users can create a four-digit PIN for easy logon to the computer. This feature is optimized for tablet PCs, but it is also available to desktop and laptop users.
Picture Password
Another authentication method, the picture password, allows users to use a set of gestures in the selected picture to login. These gestures will take into account the shape, the start and end points, as well as the directionality. However, the shapes and gestures are limited to tapping and tracing a line or circle. Microsoft found that limiting the gestures improved the speed of sign-ins by three times compared to allowing freeform methods. Wrong gestures will always deny a login, and it will lock out the PC after five unsuccessful attempts, until a text password is provided.
Taskbar
Windows 8 provides a configurable taskbar in the traditional Windows desktop that spans multiple monitors. This spanning can be turned on and off and is used to display the minimized windows. Similarly, Windows 8 provides the user with the ability to show different wallpapers on different monitors, or the same wallpaper stretched across multiple monitors. The Start button has been removed, but the user can still click in the bottom left corner of the screen to open the Start screen.
Windows Explorer
Similar to Microsoft Office 2010 and Windows Live Essentials, the re-designed Windows Explorer will use the Ribbon interface to enhance discoverability of commands and bring relevant commands to users depending on their file selection. For example, selecting photos in a folder brings up tools to rotate the photos and to start a slide show. The interface was selected to bring forward the most commonly used commands for easy access.
Additionally, Windows Explorer features a redesigned preview pane that takes advantage of widescreen layouts and the "Up" button removed from Windows Explorer in Windows Vista and Windows 7 is now included in the interface.
Windows Explorer will feature a new user interface for copying and moving files, offering both a simplified interface and an advanced interface for users to monitor the speed of the operations. Users now view all simultaneous file operations in one consolidated window, and can pause file operations in progress. A new interface has also been introduced for managing file name collisions in a file operation, allowing users to easily control which conflicting files are copied.
Windows Explorer can now mount ISO, IMG, and VHD files as virtual drives through simple right-clicks or the Explorer toolbar as compared to Windows 7 where VHDs could be mounted in a less-discoverable way, via the Disk Management section in the Computer Management MMC, or by using diskpart from the command line.
Task Manager
Windows 8 includes an overhauled version of Windows Task Manager where the following changes were made.
- The tabs are hidden by default. This view only shows applications
- Resource utilization in the Processes tab is shown with various shades of yellow, with darker color representing heavier use.
- The Performance tab is split into CPU, memory, disk, Ethernet, and wireless network (if applicable) sections. There are overall graphs for each, and clicking on one reaches details for that particular resource
- The CPU tab no longer displays individual graphs for every logical processor on the system by default. It now can show data for each NUMA node
- The CPU tab now displays simple percentages on heat-mapping tiles to display utilization for systems with many (64 or more, up to 640) logical processors.
- The color used for these heat maps is blue, with darker color again indicating heavier utilization
- Hovering the cursor over any logical processor's data now shows the NUMA node of that processor and its ID
- A new Startup tab has been added that lists startup applications
- The Processes tab now lists application names, application status, and overall usage data for CPU, memory, hard disk, and network resources for each process
- The new task manager recognizes when a WinRT application is in "Suspended" status
- The normal process information found in the older Task Manager can be found in the new Details tab
New easy restore
The Developer Preview comes with two new recovery functions, namely Refresh and Reset, both of which make a complete restore easier than a re-installation. The former keeps all settings and files of the user intact and only reverses all changes to Windows files to its original state and removes all installed programs and apps. The latter deletes all files and effectively re-installs Windows, but without any additional user input such as agreeing to license agreements or selecting a hard disk required. After a reset completes, the user will be asked for the product key and will then proceed to account creation.
Family Safety
Family Safety will allow Administrators to monitor and restrict user activity via web filtering, application restriction, and computer usage time limits.
Microsoft account integration
User accounts do not have to be local-only anymore, but can be linked up to one's Microsoft account. This has the advantage that users will not lose their settings and files, as they move from their home computer to their work laptop or to any other computer also using Windows 8, and signing in via their Microsoft account.
Windows To Go
Windows To Go is an upcoming Windows 8 Enterprise feature that will allow users to create a bootable USB Flash drive (usually called a Live USB) with Windows 8 in it, including the user's programs, settings, and files. It is planned to work on both USB 2.0 and USB 3.0, and both on legacy BIOS and UEFI firmware. In addition to that, the system will pause if the USB drive is removed, and will resume operation if the drive is returned within 60 seconds of removal.
Storage Spaces
Storage Spaces is a storage virtualization technology which succeeds Logical Disk Manager and allows the organization of physical disks into logical volumes similar to Logical Volume Manager (Linux), RAID1 or RAID5, but on a higher level.
A storage space will behave like a physical disk to the user, with thin provisioning of available disk space. The spaces are organized within a storage pool, i.e. a collection of physical disks, which can span multiple disks of different sizes and different interfaces (USB, SATA, SAS). The process of adding new disks or replacing failed or older disks is fully automatic, but can be controlled withPowerShell commands. The same storage pool can host multiple storage spaces. Storage Spaces have built-in resiliency from disk failures, which is achieved by either mirroring or striping with parity across the physical disks. Each storage pool on the ReFSfilesystem is limited to 4 PB (4096 TB), but there are no limits on the total number of storage pools or the number of storage spaces within a pool.
Device support
USB 3.0
Windows 8 will have built-in support of USB 3.0 for better power management and longer battery life.
New architecture support
Windows 8 will support System on a Chip (SoC) architectures, including ARM-based systems. On the x86 architecture, Intel Corporation and AMD continue their work on low-power SoC designs that support Windows.
Other features and changes
Activation
Mike Angiulo confirmed at Computex 2011 that Windows 8 will use OEM Activation 3.0 instead of OEM Activation 2.1 (used by Windows 7), which supposedly makes it less prone to cracks.
Virtualization
Windows 8 will also include Microsoft's Hyper-V virtualization software. Previously only offered in Windows Server, Hyper-V will now be available in client versions of Windows for the first time. The system requirements for Hyper-V are a 64-bit processor, a 64-bit version of Windows 8, and a minimum of 4 GB of RAM. Hyper-V also requires a 64-bit system that has Second Level Address Translation (SLAT), a feature that helps with memory management. Many of Intel's and AMD's recent processors support this feature, including many of Intel's i-Series processors (with Extended Page Table) and AMD's 10h family processors.
Shorter boot times
On September 8, 2011, Microsoft announced that Windows 8 has short boot times, because it saves the kernel's memory to the hard disk on shutdown (similar to the existing hibernate option) and reloads it on start up.
Boot security
Windows 8 will support the UEFI secure boot feature. This will enable a new foundation for an architecturally neutral approach to platform and firmware security. It is based on a public key infrastructure (PKI) process to validate firmware images before they are allowed to execute. A secure boot helps reduce the risk of boot loader attacks.
New Virtual Hard Disk format
Windows 8 offers a new VHD format, called .vhdx, which supports up to 16 terabytes of storage. It reportedly has built-in resiliency as well as protection from corruption that can happen during power failures. It also helps prevent performance degradation on some large-sector physical disks.
Windows Display Driver Model
Windows 8 includes WDDM 1.2 and DirectX Graphics Infrastructure (DXGI) 1.2. New features were first previewed at the Windows BUILD conference and include performance improvements as well as support for stereoscopic 3D rendering and video playback.
Other major features include preemptive multitasking with finer granularity (DMA buffer, primitive, triangle, pixel, or instruction-level), reduced memory footprint, improved resource sharing, and faster timeout detection and recovery. 16-bit color surface formats (565, 5551, 4444) are mandatory in Windows 8, and Direct3D 11 Video supports YUV 4:4:4/4:2:2/4:2:0/4:1:1 video formats with 8, 10, and 16-bit precision, as well as 4 and 8-bit palletized formats.