Best free word processor

You might not need a whole office suite, just a word processor. In case you didn't know, Windows has one built-in: it's called WordPad. It lacks many of Word's features but may be all you need.
If you must have Word, then here are a few ways to use Word for free.
Now that Microsoft has made a concerted effort to switch everyone to a subscription model for Office 365, it's even more tempting to opt for a free alternative. Our pick is LibreOffice,which is far from being a mere off-shoot of OpenOffice. For most people LibreOffice offers everything you need, being just about as compatible with Microsoft Office as it's possible to get.
If you want a suite which copies Microsoft's ribbon interface, look at Kingsoft Office Suite Free, and if you don't mind embracing a cloud based service then Google Docs is another excellent choice, especially for collaborating with colleagues.
Also, there are plenty of free PDF editors which allow you to convert a non-editable file into a format, such as .doc or .xls so you can change it.