Make sure you are installing right font in right operating system. If you download fonts in zip format, then unzip first. 

 
 
Install font in Windows 10, 8, 7
Unzip the folder containing the fonts first. Fonts cannot be installed if they are zipped.
Right click on the font file and select Install.



Install font in Windows Vista
  • Unzip the fonts first. Fonts cannot be installed if they are zipped.
  • From the 'Start' menu select 'Control Panel.'
  • Then select 'Appearance and Personalization.'
  • Then click on 'Fonts.'
  • Click 'File', and then click 'Install New Font.'
  • If you don’t see the File menu, press 'ALT'.
  • Navigate to the folder that contains the fonts you want to install.
  • Select the fonts you want to install.
  • Press the 'Install' button to install the fonts.



Install font in Windows XP
  • Unzip the fonts first. Fonts cannot be installed if they are zipped.
  • From the 'Start' menu select 'Control Panel.'
  • Select the 'Appearance and Themes' category.
  • Select 'Fonts' from the 'See Also' panel at the left of the screen.
  • In the Fonts window, select the 'File menu', and choose 'Install New Font.'
  • Navigate to the folder that contains the fonts you want to install.
  • Select the fonts you want to install.
  • Press the 'OK' button to install the fonts.



Install font in Mac

To Install fonts in Mac, double-click the font in the Finder, then click Install Font in the font preview window that opens. After your Mac validates the font and opens the Font Book app, the font is installed and available for use. You can use Font Book preferences to set the default install location, which determines whether the fonts you add are available to other user accounts on your Mac.


 
Install font in Linux Ubuntu

Double click on the font file. It will open it in Font Viewer. In here, you can see the option to install the font in top right corner. Couple of seconds later, you’ll see the status has been changed to Installed. Once installed, you can see the newly installed fonts in any application that uses fonts such as GIMP, OpenOffice.org etc.

What happens when you have like 10 new fonts to install. Installing all these fonts, one by one, by double clicking on them is disgusting. Go to your Home directory in File manager. Press Ctrl+H to show hidden files in Ubuntu. Find the folder .fonts and paste all the fonts here. Done!



Thank you!