― Most of you might be aware of the fact that it is possible to use Windows 7 and Vista for 120 days without activation. This is actually possible using the slmgr -rearm command which will extend the grace period from 30 days to 120 days. However in this post I will show you a small trick using which it is possible to use Windows 7 without activation for approximately an year! Here is a way to do that. ∙ 1. Goto “Start Menu -> All Programs -> Accessories” . Right click on “Command [...].