Since IT-guys usually stay up to date, I decided to upgrade my existing Windows 8 Pro on a Chronos 7 series notebook (NP730U3E-S07DE), which is equipped with an on-chip HD 4000 graphics card plus a dedicated ATI Mobility Radeon HD8550M.

I didn’t listen to Murphy, when he said „Never touch a running system“ and „Everything that can go wrong will go wrong“. I should have…

I used the „update to Windows 8.1“ button inside the Windows Store and everything downloaded from the Internet and installed. It rebooted, asked my all the customization questions (and tried to force me to enter/create a Live-Account, which I did not; with the trick of unplugging the machine from the Internet at the appropriate time).

But at the end of the installation, when the PC was supposed to boot into the installed system I only got a Windows 8.1 black screen with a flickering network icon. And a cursor, that I could move on the screen. But no more…

After a lot of trials and errors, here’s what finally worked for me:

1. I shut down and restarted my computer several times (via power off/on), so that a screen showed up, asking me, if I had bootup problems. There I chose Troubleshoot, Windows Startup Settings, and finally „Enable Safe mode with networking“
2. Then the PC finally booted, and the first thing I did was go into the Device Manager and uninstall the drivers of both my graphics cards (Alternatively you could also just disable them via right click, Disable).
3. With that I was able to reboot and see a normal screen in Windows 8.1 (although extremely slow graphics performance of course).
4. The first thing I did was uninstall all ATI and Intel Display software, since that was not possible in safe mode.
5. Then I had to find a suitable driver for my ATI Mobility HD8550M graphics chip, which was not so easy. Samsungs SW Update tool has no knowledge of windows 8.1 at present. And ATI mobility drivers are rare and OEMs/manufacturers don’t update their drivers so often.
   I finally found the file 13-9_mobility_win7_win8_64_dd_ccc_whql.exe, which recognized my graphics card and installed a driver.
6. I also had to re-install the Intel HD 4000 driver, to be able to normally boot into the logon screen again.
7. Unfortunately, the new/latest Intel HD driver trashed my screen brightness adjustment on my Samsung notebook computer. I tried all sorts of newer and older versions, but they all had the same flaw with the non functioning screen brightness. The version that finally worked for me was 9.17.10.2817 from a Lenovo support site: 0mvg11w8_64.exe (not that I had a Lenovo notebook, but since the chip is the same, who cares *g)
   I had to turn of automatic updates and tell Windows Update to exclude the newer Intel HD 4000 driver Intel Corporation Graphics Adapter WDDM1.2, Graphics Adapter WDDM1.3 – Intel(R) HD Graphics 4000, as it tried to upgrade the driver again, which would have brought back my brightness adjustment problem.
8. The next step involved finding and installing (or re-installing) various drivers, which did not survive the 8.1 upgrade (WLAN, Bluetooth, Mouse, etc.).
9. If you also had antiviral software, VMWare Workstation, VPN Software or any other program that installed some sort of (simulated) hardware driver, you might also have to re-install that piece of software, since it is most likely that it no longer works after the Windows 8.1 upgrade.
10. Don’t forget to run the „Disk Cleanup“ at the end of your installation to clean up over 10 GB of leftovers. (Right click C: drive, Properties, Disk Cleanup, Clean Up System Files, check „Previous Windows Installation(s)“ and accept.