Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113
You can get a pre-compiled version of grep for Windows from SourceForge
via <http://unxutils.sourceforge.net/>. It comes with lots of other
useful Unix utilities. Better yet, they use the GNU implementations of
the utilities, which have lots of nice features. (For example, all of
the programs give a concise but useful summary of their command-line
arguments and options if you use "--help" as an option.) I use and
highly recommend this project.