Oh, and by the way, Windows Search /TB 9 & 10 do not really find the term re tu rn in g as a whole.
They found re, but nothing beyond and including ret.
They found tu, but nothing beyond and including tur.
They found rn, but nothing beyond and including rni.
They found in, but nothing beyond and including ing.
And finally they found g.
How broken and busted can you get? (And yes, I re-indexed the Windows Search, in case you are wondering.)
Maybe you could use a third-party search engine instead of Microsoft's. (I seriously doubt Windows 10 is much better, never mind reasonably good, but I can not yet speak from experience.)