fatal error C1083: Cannot open include file: 'iostream.h': No such file or directory

If you are seeing this error, the ISO Standard C++ supports the inclusion of the iostream header as either

#include <iostream>
or
#include "iostream"

Background:

VC has supported two different versions of IOStreams for
several years. "Classic IOStreams", as implemented in <iostream.h> (etc), and "Standard IOStreams", as implemented in <iostream> (etc).

Note the lack of the .h in the standard iostreams header file names.
VC7.0 deprecated the "classic IOStreams" and VC7.1 dropped support for "classic IOstreams" altogether.