It's possible that when you update from driver version to version, that something can go wrong. I think that might be what happened here. So using by
DDU, you can completely remove every trace of the GPU driver, and thus, all the bugs that they may be causing. Then you can reinstall the latest driver. This
tutorial will work.
Instead of going to msconfig to disable WiFi/Ethernet, you could also simply either unplug your Ethernet or open your WiFi on taskbar and turn WiFi off from there, just make sure that it says Turn Wi-FI back on Manually so that it stays off through your reboot. Also, another way of booting into Safe Mode is by pressing Restart while holding Shift. It'll show a blue screen with some options, choose Troubleshoot, then advanced options, then startup settings, then it'll ask to restart. There will be more options and you can then press f4 to boot into Safe Mode. His tutorial should work fine though.