There is some software that will open word documents, but I don't have any names of them.
Try Google Docs.
If you're loading an old version of Office, and you have the serial number of the software, usually printed on he CD or the box, and you register it, it might update with new releases, or it might just be for bug fixes.
It won't hurt to select updates.
Microsoft Office will deal with older documents, but may not open newer versions.
If you have to open an older version, and you need to return it to sender, then don't update it to your version. Then may not be able to open it.
If document is just for your intended use, you can update it or keep it as the old version.