iPhone Unavailable Display on My Iphone 6S

I was using Windows computer and I followed the following suggested steps below. However, I did the first 3 steps but unable to proceed because the my iPhone screen did not appear in y computer.

Here are the steps, but you will need a mac OS desktop or laptop (havent tried with windows itunes) to connect the phone... Much better if you have a backup.

1. shutdown the phone (vol up, vol down, hold power)
2. before you connect the phone to the computer via cable, hold the power button to open the phone
3. when the apple logo appears, connect the cable
4. phone should now appear on your computer
5. restore backup or back to factory settings

Please assist. Thank you