Windows in Alabama are a leak path, a rot path, and a heat path, and the right call starts with the sash you can put a hand on. A bungalow sash painted shut is not the same problem as a ranch unit fogged between the panes. Say whether water came through the meeting rail or the wall around the frame.
Coastal wind drives rain at a window the way a hose would, even when the glass looks intact. Inland storms rattle old ropes and weights until the meeting rail no longer sits tight. Summer humidity fogs the interior of a cold pane and feeds mildew on a stool that never fully dries. Winter drafts on a ridge house are a different complaint from a sill that stays wet in July.
Replacement units fail in thick plaster walls when the fin is buried and the joint is caulked instead of flashed. Brick-veneer openings weep into the cavity if the sill pan was skipped. Wood sills on pier cottages go soft at the corners while the glass still looks fine. Aluminum frames on later ranch houses sweat and pit, and the latch no longer pulls the sash in.
Look at the stool, the apron, and the drywall under the window after a hard rain, not only at the glass. A stain that returns in the same corner is a path, not a mystery. If the sash will not stay up, the balance or the cord is done. If you see haze between panes, the seal is done. Those are different jobs from a lock that is merely loose.
When you call, name the floor, the side of the house, and what the storm did. Street side in a Mobile rain is not the same as a shaded north wall in Huntsville that grows mold on the trim. Say whether you want the unit to open again or you need the water to stop. Bring the count of openings that misbehave, in words, and leave the rest of the house out of the first sentence. Call the number on this page.