Lost sound

Hi all not new to here but to posting so here goes.

Basically yesterday my missus said she accidentally touch the keyboard while cleaning and listening to music and now we've lost the sound in XBMC only, I know F8 mutes it and F9 & 10 is the volume control and yes I've tried them with no joy, is the any other buttons or shortcuts that can do this or have I got to uninstall and re-install XBMC ?


Thanks
Welshboy Taffy