Vista can be installed, used and run without license or any product key. Microsoft gives 30 days grace period for purpose of trial or evaluation. If you don’t activate Windows Vista with proper activation key before end of trial period, after expiring of trial period Windows Vista will lock into Reduced Functionality Mode.

Site Neowin.net posts step-by-step instructions for extending the length of time you can run Vista without activation from 30 to 120 days.

The “secret” of extending Windows Vista activation period is a simple command prompt command: “slmgr –rearm”. With use of this command you can “rearm” activation period counter to start count again from 0 to 30 days – for up to 3 times. With this method you will extend activation time on Vista to max 120 days. Nice trick… [via]

Tags | Howto, Tips and Tricks, Vista, Windows