My bedroom window was stuck shut for an entire summer. I just accepted it. When fall hit and I wanted to close the storm window, I realized it was also stuck open — about two inches, with a gap that let in every mosquito in the neighborhood. I had been ignoring a five-minute fix for three months.

A stuck window is almost never broken. It is dirty, painted shut, or out of alignment. All three are fixable without replacing anything.

Diagnose Before You Force It

Do not muscle a stuck window. You will break the glass, bend the frame, or strip the crank mechanism. Look at the track first. Is there debris, dirt, or paint in the way? Try wiggling the sash gently side to side. If it moves but then catches, the track is dirty. If it does not move at all, it is probably painted shut. If one side moves and the other does not, the balance mechanism has failed.

Clean the Tracks Like You Mean It

Vacuum the tracks with a crevice tool attachment. Then spray the tracks with a household cleaner and scrub with an old toothbrush — get into the corners where the sash rollers sit. Wipe dry. Spray with a dry silicone lubricant (not WD-40 — it attracts dirt). Open and close the window a few times to spread the lubricant. My bedroom window started sliding like new after this step alone.

Unstick a Painted-Shut Window

If the window is painted shut, run a utility knife along the seam between the sash and the frame — all four sides. Use a putty knife to gently pry between the sash and the stop (the thin strip of wood the sash slides against). Work your way around slowly. Do not force any single spot. Once the seal is broken, slide a window zipper tool (costs about eight dollars) along the gap to cut through any remaining paint. Open the window gently.

Fix a Misaligned Sash Balance

If one side of the window drops or will not stay up, the sash balance — the spring mechanism inside the side channels — is broken or disconnected. Most modern windows use spiral balances. Remove the sash by tilting it inward (check your window’s manual — most tilt in by pressing the top sash clips). You will see the balance mechanism in the channel. If the spring is loose or the shoe is broken, take the part to a hardware store and match it. Replacement balance cartridges cost about $15-25 per pair.

Lubricate the Locks and Latches

Window locks get gummed up with years of dust, paint overspray, and corrosion. Spray a small amount of graphite lubricant (the dry powder kind for locks) into the keyhole and latch mechanism. Work it back and forth. If the lock still will not turn, unscrew it from the sash, clean the mechanism with rubbing alcohol, lubricate, and reinstall. A stuck lock is often the only thing preventing a window from opening — and it is the easiest fix in the whole list.