Windows Deployment Services. A technology from Microsoft for network-based installation of Windows operating systems based on PXE.

Windows Deployment Services is a technology from Microsoft for network-based installation of Windows operating systems. It is the successor to Remote Installation Services. WDS is intended to be used for remotely deploying Windows Vista, Windows 7 and Windows Server 2008, but also supports other operating systems because unlike its predecessor RIS, which was a method of automating the installation process, WDS uses disk imaging, in particular the Windows Imaging Format (WIM). WDS is included as a Server Role in all 32-bit and 64-bit versions of Windows Server 2008, Server 2008 R2, Server 2012 and is included as an optionally installable component with Windows Server 2003 Service Pack 2.

http://en.wikipedia.org/wiki/Windows_Deployment_Services