Measure the distance between each of the vertical studs on the bottom sill. Mark the halfway point between each vertical stud with a pencil.
Drill a hole through the bottom sill and into the subfloor at each of the marked spots.
Insert a lag screw into each of the holes. Tighten the screws until they're tight with a socket wrench.
Measure the distance between each of the vertical studs on the bottom sill. Mark the halfway point between each vertical stud with a pencil.
Drill a hole through the bottom sill at each of the marked locations. Stop when the bit reaches the concrete. Drill a hole into concrete underneath the bottom sill with a carbide-tip drill bit. Insert a masonry anchor into each of the holes in the concrete.
Insert masonry screws into each of the holes and tighten until snug with a socket wrench.