On Thu, 16 Jul 2015 11:48:30 -0700, Bob wrote:

I'm about to replace carpet and want to fix some squeaky areas at the
same time.

Since I can tear off the carpet to do this, I don't need to use those
special snap off screws for carpet, right?

Can I just use a generic wood screw (countersunk flat head)?
Is 2 inch about right length?

1 5/8" screw may do well enough

Do you have access from a basement ceiling?