An interactive television system has a centrally located head end server coupled to service multiple, remotely located set-top boxes. Each set-top box runs an electronic programming guide that provides an on-screen program grid listing program titles in relation to their scheduled viewing times and channel numbers. The viewer is permitted to scroll through the program grid to list titles of past, current, and future programs. A database, resident at the head end server, supplies the program titles and scheduled viewing times of the past, current, and future programs to the electronic programming guide. The head end server transmits real-time video data streams of the available programs to the EPG. A continuous media server, resident at the head end server, stores the video data streams to build a reserve of previously played programs. The media server can also store video preview clips of future programs. When a viewer selects a current program, the real-time video data stream of the current program is displayed by the set-top box. When the viewer selects a past program, the head end server retrieves a stored video data stream of the selected past program and transmits it to the set-top box. When the viewer selects a future program, the head end server retrieves a stored video preview clip of the future program and transmits it to the set-top box.