Wood floors squeak with nearly every step. Fix/tear-out/accept?

[Cole Stokes]

So I bought a 100 year old house that I'd like to eventually rent out, but living in there now. It has these kind of rough looking floors that I think are salvageable with a good resurfacing but they squeak almost with every step. 

The squeaks drive me nuts, I can't get to the underside without taking down the ceiling in the basement. So I just don't know what to do, I'm thinking I need to tear them out but I'm concerned about what I'll find underneath in such a old house.

I've tried a few simple fixes but I'm not getting good results:

A) talc powder - didn't seem to help at all and filled in the lines between with white powder which locked ridiculous.

B) Break away squeak fix screws, I haven't been able to get them to break I think I'm hitting the joist but not 100% sure, but even if I were I don't think I could fix every squeak and if I were able

to find the joist and consistently use these screws they'd have to be nearly every everywhere.

The worst area is the living room which is only about 300 sq feet. I don't have experience replacing wood floors and I'd like to find a way to 

resolve this without spending $10k+ to have professionals come in and remove the floor and install DVP. I'd consider doing the work myself

but I'm concerned that it might end up being pretty complicated with nasty surprises once I rip that floor out. 

Any advice would be appreciated. 

This pic isn't mine but the condition/style look essentially identical.