A failed call does not automatically mean the microphone is broken.
The problem can be at several points: Windows may not see the microphone, it may see it but receive no usable sound, privacy settings may block applications, the wrong input device may be selected, or the calling app may be listening to a different microphone than Windows is.
The useful first question is:
Can Windows itself record your voice from the microphone you intend to use?
Check whether Windows sees the microphone
Open Settings > System > Sound and look under Input.
Microsoft's microphone setup guidance uses this page to show connected microphones and to select a microphone for testing. [R1]
If the intended microphone is not listed, check the physical connection first. For a headset, check its plug or USB connection. For a Bluetooth microphone or headset, confirm that it is paired and connected.
Do not start by changing application settings if Windows does not detect the device at all. The failure is earlier in the capture path.
Test whether the microphone actually records sound
Select the intended microphone under Input, open its properties, choose Start test, and speak normally.
Stop the test and play the recorded sample. Windows also lets you adjust the input volume from this page. [R1]
If your voice is captured clearly, Windows is receiving usable audio from that microphone. If one calling application still cannot hear you, the problem is narrower than a completely failed microphone.
If the test is silent, check for a physical Mute button or switch on the headset or microphone. Microsoft explicitly lists an active headset mute control as a cause to check when other people cannot hear you. [R2]
Also confirm that the intended microphone is selected. A laptop can have several input devices at once, such as its built-in microphone, a webcam microphone, a headset, or a Bluetooth device.
Check microphone privacy access
Windows can detect and test a microphone while application access is controlled separately, under Settings > Privacy & security > Microphone.
For applications to use the microphone, Microsoft says Microphone access must be on. Let apps access your microphone must also be enabled, and desktop applications have a separate Let desktop apps access your microphone control. [R3] This matters when Windows can hear you in its microphone test but a call application cannot.
If the PC is managed by an employer or school, microphone access can also be controlled by organizational policy. Do not try to bypass such a policy; contact the administrator responsible for the device.
Check the microphone selected inside the call app
Windows detecting the microphone correctly does not mean every calling app is listening to it.
Some apps have their own audio-device setting. Microsoft Teams, for example, lets you choose a microphone in Settings → Devices, and Microsoft recommends checking it is selected there rather than assuming Teams follows the Windows default; Teams also has its own test-call function. [R5]
If the Windows recording test works but one app still cannot hear you, check that app's own microphone selection and mute control before touching drivers.
When should you look at the driver?
A driver matters when Windows does not detect the microphone, the device disappears after a system change, or it stays unusable after connection, selection, mute, volume, and privacy checks are ruled out. Do not update every driver merely because one is old.
Microsoft recommends Windows Update as the preferred way to obtain current audio drivers, with Device Manager and the manufacturer's support site as follow-up paths. [R4] A driver change should be a targeted response to evidence, not the first action after a failed call.
What should I do now?
- Check the microphone or headset is connected and any physical mute control is off.
- Open Settings > System > Sound > Input and select the microphone you want to use.
- Run the Windows microphone test and listen to the recorded sample.
- If it is silent, check input volume, positioning, connection, and mute state.
- Open Settings > Privacy & security > Microphone and confirm the required permissions are enabled.
- If Windows records you correctly but one app still fails, check that app's own microphone selection and mute control (for example Teams' Settings → Devices).
- If Windows does not detect the microphone or it remains unusable, investigate the audio driver using Windows Update first.
- If it is still absent or silent after a known-good connection and driver check, test another microphone or port to separate a PC-side problem from failed hardware.
The goal is not to reinstall audio software as quickly as possible. The goal is to establish where the microphone signal stops and repair only that part of the path.