A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Are you opening the files which is already saved?
Do you want to change the default template?
Opening the saved PowerPoint presentation from the saved template will not change the settings to the template format.
You may follow the steps to set the custom template as default:
- Click the Office button.
- Click Save As.
- Browse to the template (.potx) location and select it.
The default location for PowerPoint template is C:\Users\UserName\AppData\Roaming\Microsoft\Templates
- Name the Template as Blank.POTX.
- Click Save and verify the results.
You may refer to the following link to add slide from another presentation file and check if it helps: