I have had many people on my Facebook profile ask about cheaper ways of getting Microsoft Office or other software that will do the similar thing. There is plenty of software out there that will do exactly what you need for either a low cost for the price of absolutely nothing. The software will also open Microsoft Office documents as well. There maybe limitations mind you but some are very minor and some offer you to pay to get more out of the software.
Here is one thing you'll have to remember though. Every time you save a file remember to save it as a file that can be either readable on other operating systems or other Office software. The files that are mostly readable on other software and operating systems can be saved as rich text formats (.rtf), .doc, and .docx. That is where a lot of people have issues cause you can save it as a specific document that may not be readable on Microsoft Office.
Some of the software have different features which are good for certain businesses but if all your looking for is word processing they all usually work about the same. There is plenty of other office suites as well but below is what is most popular
Libre Office - Windows, Linux and Mac OS/X http://www.libreoffice.org/ (Free)
Open Office - Windows, Linux and Mac OS/X http://www.openoffice.org/download/ (Free)
Kingsoft Office - Windows http://www.kingsoftstore.co.uk/kingsoft-office-freeware.html (Free Shareware Based)
Word Perfect - Windows www.corel.com/wordperfect (Trial, Full $169.99)
Microsoft Office 2013 - Windows http://www.microsoftstore.com/office (multiple priced packages)