Try double-clicking the file in Windows Explorer to see if another program will open it. If PowerPoint opens again when you ...

Try double-clicking the file in Windows Explorer to see if another program will open it. If PowerPoint opens again when you double-click the file in Windows Explorer, it is possible that the file is not a PowerPoint file but that its extension was renamed to be that of a registered PowerPoint file type (such as .ppt, .pptx, .pps, .ppsx, .pptx, .pot, or .potx)  but the file is not a PowerPoint file.