Squeeky chipboard floor solutions please

Wood screws, and plenty of 'em.

Tell me more? Floor already down? Wedge shims and gorilla glue works great for spot squeeks

I recently put down hardwood on the first floor. After removing the carpet, I used 1 1/2 boxes of 2 inch floor screws (each box has 500 screws). Screws were about 3-5 cm apart! Like Sledgehammer says, lots of them. Now the floor is super tight, no squeaks anywhere.

If you have a floor down already, and the squeaks are on the first floor, if you have access to the joists from the basement, then like bikerguy says, shim and glue the areas that squeak. Have someone upstairs walking around to locate the squeaks.