Free office software suite
If you're interested in a fully featured Office Software Suite - for free - that can read and write Microsoft Office files, check out LibreOffice.
LibreOffice is "forked" (split) from OpenOffice, which still exists. LO, however, has been rapidly getting updates and has undergone a major code refactoring, which removed old bits, refined useful bits, and added lots of new features.
It's stable, fast, and a pleasure to work with. Plus, no "Ribbon" interface like Microsoft's Office now has.
GTS Computers can do the installation for you if you're not comfortable doing that yourself.