Who can I contact for advise for squeaky floors that continue to squeak after nailing down?

I live in a Condo and have squeaky wood floors, had them nailed down, but the squeak returns..... what can I do... Please help!Who can I contact for advise for squeaky floors that continue to squeak after nailing down?
I fixed our squeaky floors from under the house. My wife stepped on the floor till I saw where it was moving and squeaking. I tapped some shims in the areas that moved and then I screwed the shim in it's place. We have no squeaks at all. Easy for us but only because we have a crawl space. Some floors cannot be accessed under neath. They make special break off screws for those who can't get to the bottom of the floor.





This link shows some squeek stop kits available. Some are easy to use if you have the understanding about floor joists that can't be seen. I don't really think just anyone can do this type of this (so called) easy fix.





http://hardware.hardwarestore.com/27-106鈥?/a>Who can I contact for advise for squeaky floors that continue to squeak after nailing down?
Wood floors should always have a layer of tar paper under them to prevent squeaking. It's possible that whoever installed the floor skipped that step to cut cost or maybe didn't know. Also there should be a gap between the flooring material and the wall which will be hidden by the baseboard.Omitting that step can result in buckling and squeaking with changes in humidity.