If you click Object on the Insert tab, in the Text group, the Object dialog
box should be displayed. In the Create New tab, the 3rd choice from the top
should be Microsoft Graph Chart. If it's not there, you may need to repair
your installation,
Before you do that, I'd strongly suggest that you try Office's new charting
capabilities (Insert tab, Illustrations group, Chart). It is light years
ahead of the old charting/graphing feature that you have asked about. The
charts are far more attractive and far more flexible. Feature-rich contextual
tabs are available when you select a chart (Design, Layout and Format).