Windows PreInstallation Environment (Windows PE) 3.0 is a minimal Win32 operating system with limited services, built on the Windows 7 kernel. It is used to prepare a computer for Windows installation, to copy disk images from a network file server, and to initiate Windows Setup.
Windows PE is not designed to be the primary operating system on a computer, but is instead used as a standalone preinstallation environment and as an integral component of other Setup and recovery technologies, such as Setup for Windows 7, Windows Deployment Services (Windows DS), the Systems Management Server (SMS) Operating System (OS) Deployment Feature Pack, and the Windows Recovery Environment (Windows RE).
Most of the information here is taken directly from TechNet.Microsoft.com publically available documentation. Thanks to Microsoft them for their valuable input.
Benefits of Windows PE
Windows PE was created to help OEMs and IT professionals boot a computer with no functioning operating system. In the past, OEMs and IT professionals often used an MS-DOS-based boot floppy disk to start a computer. However, an MS-DOS-based boot floppy disk has a number of limitations that make it difficult to use for pre-installing Windows or recovering existing installations or data. It has:
- No support for the NTFS file system.
- No native networking support.
- No support for 32-bit (or 64-bit) Windows device drivers, making it necessary to locate 16-bit drivers.
- Limited support for custom applications and scripts.
- The limitations of MS-DOS-based startup disks led Microsoft to develop Windows PE, which is now the primary Microsoft tool for booting computers with no functioning operating system. Once you boot a computer into Windows PE, you can prepare it for Windows installation, and then initiate Windows Setup from a network or local source. You can also service an existing copy of Windows or recover data.
Because Windows PE is based on the kernel for Windows 7, it overcomes the limitations of MS-DOS-based boot disks by providing the following capabilities:
- Native support for the NTFS 5.x file system, including dynamic volume creation and management.
- Native support for TCP/IP networking and file sharing (client only).
- Native support for 32-bit (or 64-bit) Windows device drivers.
- Native support for a subset of the Win32 Application Programming Interface (API).
- Optional support for Windows Management Instrumentation (WMI), Microsoft Data Access Component (MDAC) and HTML Application (HTA).
- Ability to start from a number of media types, including CD, DVD, USB flash drive (UFD), and a Remote Installation Services (RIS) server.
- Windows PE offline sessions are supported.
- Windows PE images can be serviced offline.
- Windows PE includes all Hyper-V™ drivers except display drivers.
This enables Windows PE to run in Hypervisor. Supported features include mass storage, mouse integration, and network adapters.
