how to install win 7 on Lenovo IdeaPad 510s 13ISK

how to install win 7 on Lenovo IdeaPad 510s 13ISK

1. create a win7 usb boot disk with usb 3.0 driver

2. prsee novo button to setup bios to usb legacy boot

3. insert win7 usb boot disk to usb 3.0 port

4. insert mouse to usb 2.0 port

4. press novo button to boot from usb disk
   then install win 7