How to fix the chart data

To convert the chart to a picture, you can use two different ways:

First way: copy the chart as a picture

To copy the chart as a picture, do the following:

   1.   Activate your chart.

   2.   On the Home tab, in the Clipboard group, choose Copy and then click Copy as Picture...:

   3.   In the Copy Picture dialog box, accept the default settings or change that you want and click Ok:

   4.   Click any cell to deselect the chart.

   5.   On the Home tab, in the Clipboard group, choose Paste (or press Ctrl+V) to paste the picture at the cell you selected.

Second way: paste the chart as a picture

To paste the chart as a picture, do the following:

   1.   Activate your chart.

   2.   On the Home tab, in the Clipboard group, choose Copy (or press Ctrl+C).

   3.   Click any cell to deselect the chart.

   4.   Do one of the following:

• On the Home tab, in the Clipboard group, choose Paste and then click Paste as a Picture:
  
• On the Home tab, in the Clipboard group, choose Paste and then click Paste Special...:
  

  In the Paste Special dialog box, choose the format of your picture:

  

See also How to freeze charts and other objects in Excel.

See also this tip in French: Comment fixer les données de graphiques.