A relatively little known trick to extend Microsoft Office's 30-day trial period up to six months has been around for several years. The process in question revolves around a rearm command, aimed at enterprise administrators who use a single copy or image to deploy the software company-wide, which can be run a maximum of five times for an extra 30-day grace period each before having to enter an activation key.

This was the case with Office 2010, it's still there on the newly released 2013 edition, and now the folks at How-To Geek report that the same trick works with the subscription-based Office 365 package.

The procedure is exactly the same, too. Simply open a command prompt window as administrator and run a file named "ospprearm.exe" which should be located in %installdir%\\%Program Files%\\Common Files\\Microsoft Shared\\OfficeSoftwareProtectionPlatform, where %installdir% is "C:" on most machines and %Program Files% will be the Program Files (x86) folder If you installed the 32-bit suite on a 64-bit version of Windows.

As mentioned above, the command can be used up to five times, and if used at the end of each 30-day grace period, you can run Office 365 – and the regular desktop editions – for up to 180 days without paying a dime.

As a reminder, if you have a valid .edu email address you can score an even sweeter deal for Microsoft's subscription based productivity suite. All you need to do is register at officeforstudents.com for a three month trial – or double that if you share the deal on Facebook – and after the trial period is over a license for the educational package costs $79.99 for four years and is good for up to two PCs or Macs. Students can renew the offer one time, so in total they could theoretically get eight years of Office 365 for just $160.

Microsoft has been touting the subscription-based Office 365 over its desktop counterpart. According to the company, the web-based suite will be updated more frequently with the latest features and allows small businesses and households with up to five computers or mobile devices to access everything for one price.