Look at the picture and tell me if I can update to iOS 7 through the computer still?

I live in Virginia beach a guy who owns ntelos sells used iPhone 4S I got one and it was flashed so I could use it. They gave me the paper in the picture and to follow the guidelines. But I really want to update my iphone4 to iOS 7 is it still possible. Btw: there called the phone guys they basically can flash phones and I'm on ntelos with a frawg plan

It says do not attempt Over The Air Updates(which means straight from your phone). If you do want to update, you CAN use your computer. Though if you're still unsure, you can always call the guy you got the phone for just to be sure.