Did you ever noticed those fancy fluffy picture preview thumbnails on your desktop? If not you can activate them in the Windows File Explorer by removing a checkbox for an option called “Always show icons, never thumbnails”. At Sevenforums.com they wrote a nice tutorial how to do that.
But this tutorial is about the PowerPoint preview thumbnail, maybe you noticed sometimes when you saved your presentation and then afterwards modify the first intro slide the preview thumbnail will not change reflecting your changes. This is because Powerpoint created a static picture from the first slide which is used as a preview thumbnail. Personally I’m a sucker for detail as your presentations reflect your work and accuracy so in my opinion this sucks!
Luckily there’s a solution
Saving with a different filename is not going to help you. So how do we wash this little piggy?
Open your presentation and go to the backstage area (the red colored tab labeled File).
On the right side you find some metadata which is included whit the file. Next to the word "Properties" you see a little pulldown arrow.
Choose "Advanced Properties" and go to the "Summary" tab in the dialog box which opens.
At the bottom you see a check box "Save preview picture" which is checked. Uncheck it and click Ok.
Now you can save your presentation. The old preview thumbnail will change to the default PowerPoint icon.
Now you need to run the Windows Cleanup utility "Disk Cleanup". You can open it by going to Start >> Run and type “cleanmgr” in the dialog box.
After you cleaned the cached files you open the presentation again, re-check the Save preview picture checkbox again and save your presentation.
Maybe you need to refresh the folder or hit F5 but you’ll notice your changes from the first slide have been changed to the little preview thumbnail.