Here's a quick trick for if you slacked off and need an extra day for a project, It makes a fake PowerPoint file that won't open.
1.)Go to your control panel and find the folder named "Folder options" and open it.
2.)Go to the View tab and make sure "Hide file extensions to known files" is selected.
3.)Now find a random .dll file, Copy it to your desktop, and rename it to "(what you want the name to be).ppt"
4.)Test it to make sure it doesn't open.
5.)Now for the final step, FINISH YOUR PROJECT!