Microsoft Word is a word processing program that is commonly used in businesses, colleges, libraries etc. It's a commercial program so you have to pay for it if you want it installed on your computer, but there are free word processors available such as:
Or you could sign up for an Outlook email account which comes with a free version of Microsoft Word. It doesn't have all the features of the full version though, and you have to be connected to the Internet to use it. Windows computers usually come with a free basic word processor called Word Pad so you could use that instead.
This should work if you have Windows 7 or later.
Word should now start up.