I use e PC with both Ubuntu and Windows-7 OSs. I tried to install the Calibri font for Ubuntu in this way: I did open the calibri.ttf file in the Windows/Fonts directory using Font Viewer and clicked on the Install button. Now I need to disintall that font but I can't. Font Viewer shows me "Calibri Regular" font is installed but does not allow me to disintall it. Font Manager does not show Calibri in the font list. Character Map does not show Calibri in the font list. Ubuntu Software Center and Synaptic don't find anything like "calibri". There is no calibri file in those directories: usr/share/fonts usr/local/share/fonts ~/.fonts The font is visible to LibreOffice, Chrome, Firefox.