On a Windows computer, depending on your system, you may be able to double click on the horn icon in your task tray and then increase the master volume. The RealPlayer window contains a volume control that can be adjusted as well. I get sound but no picture. Your connection may be too slow to play the video. Some factors that affect the speed of the connection are the quality of the phone line, the capabilities of your Internet service provider, the traffic through the provider's system, and the general traffic on the Internet.
Several things can affect the sound.
If there's no picture, the connection speed may not be fast enough, as explained above. Pauses are caused by a slow connection. When the data packets aren't coming in fast enough, RealPlayer will have to stop playback until it receives enough of them. This could be caused by the quality of the phone line, the capabilities of your Internet service provider, the traffic through the provider's system, or the general traffic on the Internet. It was working, but it stopped.