Windows: Microsoft offers free 30-day trials of Office 365 and Office 2013. After your free month is over, you won't be able to use some major features of these office suites. One little-known secret, however, is you can actually extend your trial five times, for a total of 180 days of use.
The How-To Geek offers the instructions to extend your test drive using a built-in tool provided with Microsoft Office, OSPPREARM.exe. You'll need to repeat this process every 30 days if you want to keep "rearming" the trial, but this gives you nearly half a year of Microsoft Office access for free. Hit up the link below for the simple instructions.
How to Extend Your Office 2013/365 Trial to 180 Days [How-To Geek]