Pro jistotu si ještě pročti toto:
https://support.lenovo.com/cz/cs/solutions/ht118432-webcam-or-camera-not-working-or-cannot-turn-on-in-windows-81-10-ideapad-thinkpad
Ovladač jsi instalovala tenhle?
https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/lenovo-g-series-laptops/g70-70-laptop/downloads/ds103883