I have a Samsung NP300E5V with Radeon 8750M, I had similar issues, Black Screen in my case and same error code 43 as you with drivers fom Samsung website on Windows 8.1 (Worked on Windows 7). I use the drivers from AMD website now, without such issues.
Samsung has not updated any GPU drivers for Windows 8.1, last was for 8 and those drivers cause issues with 8.1 as you and I have had. Even laptops coming with 8.1 do not have AMD drivers on their SWUpdate utility, you can check for yourself. I spoke to them and they do not even have a timeline for upating, and simply told me to use drivers from AMD/ATI website.