First- did you unzip them? If not , do so- I'm assuming that you know how. (I recommend putting them somewhere that you would remember where you put them.) Then, go to your control panel. (In XP it should be on your start menu as a separate entity; in all the other versions it is in the start menu under 'all progams' then 'accessories'.) You should see a folder icon labeled 'fonts'. Double click on it. You should now see a list of all the fonts you have installed on your computer. Go to 'file'. Under 'file' it should say 'Install New Font...' . Click on it- a box should come up. In the box there is another box where you see folders. Navigate to wherever you put your fonts- again, I'm assuming you know how. Your fonts should pop up in the top box which was empty before. Select the fonts you want to install or click 'select all'. Then click 'OK'. The fonts you selected should now start to be installed. When they are finished the boxes will close and you'll see the fonts folder again- this time, with the fonts you just installed included. Close the fonts folder. Now you can use your fonts on any program that lets you change the font-- including word processing programs!
I've downloaded fonts but how do I use them? e.g in a word document