There is a 1cm thick white strip down the left side of my screen

Hello,
I tried e-mailing HP about my problem yesterday as soon as it happened but I still have not heard back and I'm getting worried about my laptop.
So I was using my laptop yesterday morning and it was completely fine, a-okay, but I shut it down, put it into its bag and then headed off to work, I had it turned on again approx. 40 minutes later and now there is a approx 1 cm thick white strip down the left of my screen and I want to know why. Everything that should be where the strip works fine, it just won't show anything where the stripe is.
I restarted the computer, done a hard reset.
I saw something about pressing F10 when booting up laptop but when I attempted that it caused my laptop to beep really loudly ,like it was about to explode so I just turned it off again and since then I've just been using it as normal (with the stripe done the side).

Any help would be greatly appreciated.