Is it a digital watch or a wind up merchant ? If it's the former, you will not have to do anything other than check that the hands actually move (as per kronos - as opposed to kairos - time). If they don't then there is a large possibility (like 95%) that there is no battery installed - check the box for the missing item.... However, if the watch is of the latter sort, then you may well have to actually *wind it up*...... there should be some sort of little gizmo (wheel) on the side of the watch. There is another sort of watch though - an automatic, which never needs winding up - could it be one of them ?
Where did you buy this *watch* anyway, Ratners ? (talk about no after sales service, doh .....)