There is no free system that Im aware of that will look at all s of document stored on Google Drive and index the content. I use a search app called X1 | Knowledge revealed s which will index my hard drive plus other external sources though not including Google. It not free. It does search emails and give lots of other options. There is an alternative Copernic Search - Search Technology to instantly find files emails documents & much more! But that more of the same. I also use Evernote (you may have noticed) which will directly to files in Google Drive but does not search the content. The paid version of Evernote will index PDF and MSOffice files* - but again not free. I do pay for Evernote but I find it best if I include my to Google Drive in a note with an Executive Summary of what in the file. Then if Im searching for any documents on Dark Matter (not usual) I can jump directly to the (s) I have then to the files. I use the inbuilt search options to find specific terms - and will maybe add those searches to my Exec summary so I can find them again later if need be. Ill watch this topic because I be interested in a free easier option - but I doubt one exists *Edit - when theyre part of the Evernote database. Google Drive files are not.