JFZ90
a subs based model would annoy me enough to make me go elsewhere.
You could go to OpenOffice, as I have done. It includes a text editor, spreadsheet, slide-preparation / presentation, etc. All compatible with MS and OO runs on the various incarnations of Windows, Apple, and Linux. Known to work on Win XP, 7 and 8/8.1, as well as OS X and Ubuntu/Mint Linux. I can show you OO* running on all these.
Its user interface doesn't change every time there is a wind-shift at Redmond.
And it's free.
* Ubuntu/Mint use LibreOffice, which is a 100% clone.