What does Emacs on w32 know that grep can't figure out?

[Lennart Borgman]

I saved to a file with CCleaner the list of installed programs on my
pc. This file is maybe a text file, maybe not. Emacs can read it and
think it is a text file (I believe) with

  buffer-file-coding-system is a variable defined in `C source code'.
  Its value is
  utf-16le-with-signature-unix
  Local in buffer install.txt;

However trying to search this file from a cmd prompt with (gnuwin32)
grep does not work. And it does not work with cygwin grep either. They
think it is a binary file (even though I changed the line delimiter to
unix style).

What is going on? Is grep sometimes useless on w32 now, or? (How do we
handle that in Emacs?)