Mouse and keyboard not working on lock screen login

Make sure that your computer's Unified Virtual Hid is working properly.

1) Open Device Manager (e.g. via start menu > search device manager)

2) Click “View > Device by connection”

3) Verify that “Unified Virtual HID” is in the list

4) Right-click it and select “Properties”

5) Verify that the device status is “This device is working properly”