I have a 3/4" plywood subfloor with a vinyl tile floor in my room. There is carpet (it will be removed) over it. The tile looks old, but in good shape.

I am looking to put engineered wood (1/2" or thicker) or 3/4"solid wood down. Can I staple or nail a floor down of either or both?

Should I just bite the bullet and take up the vinyl? If so, I am worried about it being level after pulling up the vinyl.

Thanks for any help. I really would like to knock this out this week, and I am having trouble finding "real" answers on these questions.

Are those vinyl tiles glued directly to the 3/4" plywood subfloor? If they are, then you can nail a hardwood floor directly over them. I would still lay the felt paper though. But make sure the tiles are not laid over a 3/8" particle board underlayment that was laid over your plywood subfloor. Even if the tiles are over a PLYWOOD underlayment, you could still lay a new floor over them after renailing the existing underlayment if needed. These are the "real answers". Count on it. You should still lay the new hardwood floor at right angles to the floor joists.