First, you're going to upzip your font folder. Once you've extracted the files somewhere on your computer [maybe to your desktop], you will do the following:
Start Menu > Control Panel > Fonts
Once this folder is open, you're going to paste your .RTF or .TTF file into the folder. It'll have a litte install window pop up and then when it's done installing it will go away. It shouldn't take it more than 5 or 6 seconds to install.
And, when your font is done installing, you can use it in MS Word, Notepad, WordPad, or any other text editing program on your computer!
Good luck!