:helpg[rep] ...
	Grep by help. Results go to the quickfix list
:lh[elpgrep]
	The same as above, but use location list for the results


:gr[ep]!...
:vim[grep]!...
	Grep using vim internals
:cw[indow]
	Open a quick-fix (result-list) window
:cn
:cp
	Go to the next/prev match (usually we map these action to hotkeys)
:lw[indow]
	Open a location-list window.
	

Samples:

:[max_num]vim/<your_pattern>/gj **/*.<your_file_ext>
	g - every match is added (without - every line is added)
	j - do not jump the firs match
	! - abandon any changes in the current buffer

http://stackoverflow.com/questions/3108588/vim-greps-wildcard-doesnt-work-in-windows