A new problem, suddenly no sound where previously sound was available with both WMP and RealPlayer. Problem may have coincided with downloading latest WMP security patch (KB917734)but deleting this patch did not return the sound. Windows 98SE operating system, no problems with sound device in Device Manager (on-board Realtek AC'97 installed). Already tried uninstaling WMP and reinstalling with no effect on problem. Sound volume set to max with 'mute' set off. Elsewhere sound is O.K.; DVDPower, etc. PC has dual boot, XP on second partition and here WMP and Realplayer play the same files complete with sound.