You’ve seen it before: that ugly white fog sitting between the two panes of glass in your living room window. You wipe the inside, you wipe the outside, but the haze won't go away.

This is a temporary fix (lasting 1–5 years), but it costs about $20 vs. $300 for a full replacement.

Look for plastic strips holding the glass in place. Pry these out carefully with a putty knife. Label which side is up.

You need three numbers: Width, Height, and Thickness (to the 1/16th of an inch). Order a replacement insulated glass unit (IGU) from a local glass shop. Bring them the old unit if possible.

Most double hung windows have side tabs. Push them in and tilt the sash out. Lay it on a workbench.

This requires precision, but it is the correct way to restore the window to like-new condition.