Open the PowerPoint file you wish to have the Excel file linked to. Launch Microsoft PowerPoint by selecting it on from the start menu. Once it launches, you can either open an existing PowerPoint presentation or create a new one by clicking the File button on the upper-left corner of the menu bar.

Choose where you want to insert the Excel file. On the PowerPoint presentation, click on the text field you want to insert an Excel file then click on the Insert tab on the upper-left section of the window to view the Insert toolbar.

Click on the Object button. This will open a small window called Insert Object.

Click on the 'Create from file' radio button. This will allow you to insert an existing file to your PowerPoint presentation, in this case, the Excel document.

Select the file to insert. Still on the Insert Object window, click on the Browse button and use the Explorer to navigate to the location of the Excel file you want to link. Once you've found the file, select it and click Okay.

Make sure that the link works. Go back to Microsoft Excel and change any data in any of the cells. Once you've edited one of the cells, go back again to PowerPoint. The data on the Excel object on your presentation should reflect the same changes you made on the Excel file.