To toggle between OSD Show/Hide: depress [i]-key.
To disable OSD (On Screen Display):
(rightclick >) Options > Preferences > Video > [OSD]
uncheck "Enable OSD".
If that doesn't help to remove OSD from screen, please
verify (with a media-file loaded) OSD-options of the codec/filter used: (rightclick > ) Options > Filters > Advanced To open the codec/filter's options click on it (maybe also click on the smaller [+]-signs to see more info); then disable OSD in that filter. (Most probably it is an ffdshow-OSD-message which is annoying you, in which case click on [+] ffdshow Video Decoder or - for tekmus - on [+] ffdshow Audio Decoder then click on ffdshow and (in the middle column) deselect OSD )