Download the compressed font file to your desktop then...
Close any running programs.
Download the compressed font file to your desktop (.zip) and extract the files inside with the free program, Winzip.
Place the font files from the zip onto your desktop.
Select all the files and RIGHT mouse click.
You can now remove or store the Zip/font files from your desktop.
For MAC (OS10 and above):
Download the compressed font file to your desktop (.zip) and double click to extract a folder, with the font files inside.
Close all running applications.
Double click on each font icon. A window will open for each. At the bottom of these windows is an "INSTALL" buttton. Click the button for each font. Fontbook will open, displaying the installed fonts.
You may now safely delete leftover files from your desktop.
Re-open your programs and the fonts should be available for use.
Install only one file-type version of any given font (either the Truetype [mac/pc], Postscript[mac], or Opentype [mac/pc]).