I created Index with just filenames ( based on answer: If you just want to include file names then uncheck ALL the boxes apart from 'Include file names for non-content file types'.)
Now I would like to search for all png files with on g: drive, with refresh in filename.
if I try this:
png g: refresh it doesn't show any results,
if I do *g:png or g:\ AND png will find all filenames starting with letter g, like g-plus_black.png**