When you want to call up that template, here's what you do. In your MS Word, click on 'File' (take note that you don't click on the File icon, but the word, 'File.' When you do so, a dialogue box appears from where you can choose the template you just created.
But first, let's learn how to create a business letterhead in Word. You only need two things: Microsoft Word and a ready graphic, preferably not wider than 5 inches and higher than 2. In other words, not larger than 5x2 inches. This is, of course, ideal but not necessarily set in stone. Let's begin. Fire up your MS Word. I'm using MS Word 2003 and you might have a different version, but I believe there is not much difference.