Try this in order:
- Check the mouse and keyboard hardware first.
- Unplug the USB cables, wait a short time, then plug them back in.
- Try a different USB port.
- If a USB hub is being used, remove it and connect the mouse and keyboard directly to the PC.
- If the devices are wireless, replace or recharge the batteries. For a USB wireless receiver, unplug it for about 10 seconds and plug it back in.
- Test the mouse and keyboard on another PC. If they do not work there either, the device may need to be replaced.
- Run Windows Update again.
- After a major Windows update, some device drivers may not migrate correctly.
- Open Check for updates from the taskbar search, then select Check for updates under Windows Update.
- This can locate and reinstall missing device drivers.
- Update the mouse and keyboard drivers manually if needed.
- Search for Device Manager and open it.
- Find the affected device in the hardware list and double-click it.
- Open the Driver tab, select Update Driver, and follow the prompts.
- Restart the PC after updates or driver changes.
- This can refresh drivers if recent updates caused the issue.
- If the problem started immediately after a Windows security update, uninstalling that update from the Windows Recovery Environment can help.
- Warning: uninstalling an update removes recent security fixes.
- To enter Recovery Environment, interrupt startup by holding the power button to force shutdown as Windows starts loading. Do this twice. On the third start, Windows should enter the Recovery Environment.
- From there, use the option to uninstall the update that caused the problem.
If the mouse and keyboard work normally inside Windows Recovery Environment but not after Windows starts, that points more toward a driver or update issue than failed hardware.