Want to darken your screen during a PowerPoint presentation? There are several ways to accomplish this. If you are using a newer version of PowerPoint, simply press the B key during your presentation to make the screen go dark. If you want to embed a black screen in the presentation itself, you just need to create a blank slide with a regular black background or black image. Place the black slide where you want to pause during your presentation.
Steps
Method 1 of 2: Pressing the "B" key

Step 1. Press the B key during the presentation
If you have a recent version of PowerPoint installed, this hotkey should darken your screen. This can be useful if you need to:
- pause the presentation to grab the audience's attention;
- discuss a topic that is not relevant to the current slide;
- show a blank screen at the beginning or end of the presentation.

Step 2. Start your presentation
To get started, launch your PowerPoint presentation. Start Presentation Mode or go to Slide Show. You can also start a slideshow by pressing the F5 key.

Step 3. Press the B key
When the moment is right, simply press the "B" key on your keyboard. If you have one of the latest versions of PowerPoint, this key should make the screen go blank.

Step 4. To return to the presentation, press the "B" key again
Press the W key to turn the screen white. Click it again to return to the presentation.
Method 2 of 2: Adding a Black Slide

Step 1. Try to just add a black slide
It's a pretty easy way to embed a black screen right into your presentation. This way you don't have to worry about pressing the B key. You can schedule the black screen so that the audience can focus on your words, and then move on to the next slide when you're ready to continue. Before moving on to the next slide, add a blank slide with a regular black background, or have the words go out.

Step 2. Find the "Layout" button and select "Blank Slide"
This will remove all text boxes from the slide. If there are still graphics on the slide, choose Design> Background> Hide Background Pictures.

Step 3. Color the background black
Click on Design> Background Styles. Select Black Screen from the options provided. Alternatively, click Format Background> Fill> Solid Fill> Color. Choose black from the list. Then click the Apply button to repaint the background of the selected slide black.
If you want to change the background color to black for each slide, click the Apply to All button

Step 4. Save the file
Click the File tab and select Save As. Save the Powerpoint file in an easily accessible place and give it any name you remember.
Be sure to save your presentation after making major changes. This is in case your computer freezes, there is a power outage, or you just forget to save your work

Step 5. Review your presentation
Before presenting your presentation to a group of people, make sure the screen dims exactly when you need it. Click on the slideshow icon in the lower right corner or on the "Start Slide Show" button in the bar at the top of the screen.