A rectangular window opening in a structure is provided with four channel members that provide a decorative frame around the opening. Three of the channel members are permanently fastened to the structure through a flange on the channel. The fourth channel member is removably fastened in place. When the opening must be covered by a storm panel, the fourth channel is unfastened and removed. A rigid rectangular panel is mounted in the three channels. The fourth channel is then mounted on the fourth edge of the panel and then the fourth channel is removably fastened to the structure. All of the elements except the panel remain in place. The panels have no holes or accessories. All panels are interchangeable for the same size window. No tools are needed to mount or remove a panel.
