I personally use an app called Everything[1] since I moved to win10. Win10's search indexing seems to be trash and its tendency to prioritize web results over desktop results is infuriating. Everything is good for finding something tucked away on your hard drive(s), is dead simple to use (give it a few minutes the first time around to index everything, then just search). I wish I could replace the existing Cortana with it or something else rather than opening a different app, but alas When in Windows, do as Microsoft demands.