The URL www.cygwin.com provides standard Unix utilities for Windows. Included
in the distribution is the so-called GNU C compiler, gcc. The Cygwin site
has a startup file that you can download and execute. This, in turn, will
install the Cygwin utilities on your computer.

However, the gcc compiler is not part of the standard or default install.
During the install, you'll get a list of packages. Expand the Devel (for
Development) tab and pick gcc, the C compiler, as one of the packages to
include. Once installed (for example, in C:\cygin), the directory

                 C:\cygwin\bin

will contain the executables, including gcc.exe. It's easiest to set your
system path to include C:\cywin\bin so that you can, for example, do

                gcc hello.c

from any command-line prompt.