No, CTRL+SHIFT+ENTER will not work. The easy way to get CMD (or powershell, gives same result for doing commands), is to press the Windows key on the keyboard, then while holding it, quickly press the X key, let go both then press the A key. This will open a UAC (is is ok to proceed) window, just asking if Administrator mode is OK, click the YES box. You should then get either a Command Prompt (black window), or a Blue window, that is Powershell (it depends on how your system was configured), then key in your sfc /scannow command (note the space needed between the sfc command and the qualifyer, that is needed, or it will not recognise it as a proper command).
When it is all completed (may take a while, so don't think it has hung at 66% and 86% or so, give it time to finish). If it asks for the PC to be retarted, do that, but if not and it DOES fix something, reboot anyway. Note that the command exit will close the cmd or Powershell window.