The window in my bedroom had been painted shut for three years. I know because when I finally tried to open it — on a 75-degree spring day when all I wanted was fresh air — the sash would not budge. I pushed harder. The glass creaked. I stopped immediately.

Breaking a window while trying to open it is the kind of irony you do not need on a Saturday morning. Here is what worked without cracking the glass.

Start With a Putty Knife, Not Your Arms

If the window is painted shut, slide a stiff putty knife between the sash and the frame. Work it all the way around the perimeter — top, bottom, both sides. You are breaking the paint seal, not prying the window open. The knife should slide in easily between layers of paint.

Lubricate the Tracks

Wood-on-wood tracks swell with humidity and seize up. Spray the tracks with dry silicone lubricant — not WD-40, which attracts dust and turns into gummy sludge. Silicone dries clean and slick. Spray into the tracks, let it sit five minutes, then try the window gently.

For vinyl or aluminum windows, a bar of plain soap rubbed along the tracks works as a dry lubricant and costs nothing.

If It Is Still Stuck

Use a block of wood and a hammer to tap the corners of the sash — gently, from the inside. Alternate corners. You are trying to break the friction bond, not force the window through it. If you hear cracking, stop. That is the glass, not the paint.

I got my window open in about twenty minutes. The putty knife did most of the work. The silicone kept it sliding smoothly for the rest of the season.