Users can type letters in one of the basic text-editing programs that are included in operating systems. On a Windows machine, Notepad or WordPad is available, while Macintosh computers are equipped with a program called TextEdit.
To create a text file using Notepad, click the Start button in the lower-left corner of the screen. Locate the search box, type "notepad" and push Enter. Notepad opens to a blank document. After composing the letter, click on File and then Save, to save the document. WordPad is opened using the same method, and has more options available for formatting text.
If using a Macintosh computer, open the applications folder and locate the icon with the label TextEdit. Double-click on the icon to open the program, and click File, and then New to create a new document.