How to Install IIS 7 on Windows Server 2008 R2

Internet Information Services (IIS) — formerly called Internet Information Server — is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows. IIS 7.5 supports HTTP, HTTPS, FTP, FTPS, SMTP and NNTP. It is an integral part of the Windows Server family of products, as well as certain editions of Windows XP, Windows Vista and Windows 7. IIS is not turned on by default when Windows is installed.
http://en.wikipedia.org/wiki/Internet_Information_Services