To Enable the Web Server role use Control Panel > Programs and Features > Turn Windows Features on or off.

The basic required IIS features are:

•ASP

•ASP.NET 3.5

•IIS Management Console

•IIS 6 Metabase Compatibility

•Default Document

•Static Content

Optionally, also enable ASP.NET 4.5 and Web Sockets as they are used in Field Connect and could be required in future updates.