I don't know how many times I've read "Windows doesn't have 'grep'. You'll have to write your own or, better yet, install cygwin!", or some variant thereof. In fact, I came across this again today.
Comments like this are usually then followed by a hoard of "my favorite grep clone is <insert random .bat file here>".
Before you go running to the web looking for a grep clone, just type 'findstr /?'. It even does regular expressions and recursive searches.