Sometimes Excel disables all add-ins that are unknown to him.
So BeGraphic might be disabled by Excel.
To reactivate it, please follow these steps
If you use Excel 2007 or laterClick on Office button and then on "Excel options" button
Go to the tab "Add-ins"
Select "Disable items" in the combobox and click "Go"
If you use Excel 2003 or earlierClick on the "Help" menu and then on "About microsoft Office Excel
In the window click on "Disabled items" button
Then on the dialog window select "Begraphic" and click on "Enabled" button
After restarting Excel, you should see the BeGraphic menu