Question Black screen when attempting to access command prompt from advanced startup ?

[help4whistling]

I'm trying to upgrade from legacy BIOS to UEFI, and I cannot access the command prompt from advanced startup. I have had issues with the screen going black before outside of this (not too frequently), but refreshing with Windows key + ctrl + shift + B has almost always done the trick. I have tried Windows key + ctrl + shift + B when encountering this particular problem, but it doesn't work. I also notice that when the screen goes black, the num lock key on my keyboard turns off and on as though there are connection issues.

Here are my specs:

Intel Core i7-4790 CPU @ 3.60 GHz
8 GB System RAM
Intel HD 4600
Windows 10 64-bit
500 watt Corsair psu

 

[Lutfij]

Your specs are incomplete. You should mention the make and model of your motherboard as well as it's BIOS version. Please include the make and model of the PSU and it's age as well.