First, check your microphone is working in Windows Settings > System > Sound > Input > Test your microphone
We strongly recommend using an external microphone or the microphone of a headset for the recording rather than a computer’s built-in microphone. This minimises external noises which will be coming through when the built-in microphone is used.
Open your Presentation in PowerPoint then follow the steps below, or watch this step-by-step video guide to recording audio. Be aware that if you choose to record video for your presentation (rather than just audio), please do not site in front of a light source otherwise your face will be in silhouette.