To keep using Office trial version for 180 days, you can run a simple command five times on every 30th day of trial, this way you will gain 30 more days of trial for five times. But, there is a trick that you can use to extend Office trial without spending and use it for 180 days which is about six months. After 30 days of the trial period, you have to pay and activate the license. Microsoft offers to download and try Office products for 30 days without paying anything.