you can use a program like winzip to unzip the .zip files. ( http://www.winzip.com )
then place the .ttf files that you extract from the .zip file into your C:\Windows\Fonts folder
have you cheked that folder with windows explorer to make sure that the font files ( .TTF ) are actually there?
if yes then just move those .TTF files into your C:\Windows\Folder
after you installed the font you wanted, you should be able to use it in most of the programs that allow you to select a font for one purpose or another. For example you can change the font in Word. In most cases you will have to restart the application before you can use the font that you installed while the application was open.
Register and/or login to access this feature.