If you have the money, and would like it invest it on Microsoft Office, go ahead.
But, I would strongly recommend LibreOffice. It is a fork of the OpenOffice project (by Oracle, formally handled by Sun Microsystems, two very respectable companies and innovators in the tech field).
LibreOffice is open source, and free! LibreOffice is very compatible with Microsoft Office, and also supports the .odt file format, and has many of the great features of other office suites such as MS Office.
LibreOffice can be downloaded from the website here -> http://www.libreoffice.org/
If you're wondering whether it will harm your computer or not, I can assure you, it is a safe download, one that you will not regret. It will take some time to download and install though, depending on your Internet connection and other factors.
If you have any other questions, edit your question and I'll edit my response.
Glad to help.
Edit: LibreOffice is available on Windows, Mac OS, and most Linux distributions. :)