Microsoft Personal Web Server (PWS) is a scaled-down web server software for Windows operating systems. It has fewer features than Microsoft's Internet Information Services (IIS) and its functions have been superseded by IIS and Visual Studio. Microsoft officially supports PWS on Windows 95, Windows 98, Windows 98 SE, and Windows NT 4.0. Prior to the release of Windows 2000, PWS was available as a free download as well as included on the Windows distribution CDs. PWS 4.0 was the last version and it can be found on the Windows 98 CD and the Windows NT 4.0 Option Pack.