Open your PowerPoint presentation
Go to the slide where you want to add narration
Click the Slide Show tab
Select Record Slide Show
Choose Record from Beginning or Record from Current Slide
Allow PowerPoint to access your microphone if prompted
Start speaking clearly into your microphone
Use the recording controls to pause, stop, or move to the next slide
Continue recording for each slide as needed
Click Stop when finished
Save the presentation to keep the voice over
Play the slideshow to check the audio
Adjust microphone settings or re-record slides if needed