in explorer, go to file>folder and search options
go to search tab
see if you have "always search file names and contents" (second option) selected
default is first selected.
i had slow search from start bar too, but after i switched to second option, it restored the fast search. nonetheless, search doesn't seem to work for me. i can't actually search in my file contents...not sure why. as in, i have certain words i'm searching for in a word document, but search doesn't pick it up when it's indexed. it only searches file names and descriptions.