Microsoft Office requires activation within 30 days and can be re-armed up to 5 times, extending activation by 30 days each time. Activation cannot be re-armed after successful activation, even with a trial key.

By rearming on the last day before activation is required, this tool allows for an extended evaluation period of 180 days (6 * 30). While the rearm feature was designed with corporate users in mind, it's an official feature and there's no risk of illegality associated with its use.
It's important to note that the tool only works with RTM (14.0.4760.1000) or later versions of Microsoft Office 2010. It's incompatible with "Click-To-Run" versions, which are virtualized trial versions, and doesn't appear to work with 60-day trial versions either. Overall, Microsoft Office's rearm feature is an excellent option for users who need more time to evaluate the software's full functionality.
Version 1.0.0.7: bugfixes