Linking PowerPoint File to the Excel File
Each time you open a PowerPoint presentation that is linked to another Microsoft Office product, such as Excel or Word, you will be prompted to update the links in the presentation file.
If you trust the source of the presentation, then choose to update the links. All links to other documents will be updated with any new changes. If you choose the Cancel option in this dialog box, the presentation will still open, but any new information contained in linked files, such as an Excel chart, will not be updated.