How can I fix the no screen error on xserver startup on Linux?

When I try to start my Debian 9 xserver, it shows a black screen. Xorg -configure outputs > Number of created screens does not match number of detected devices and outputs a non-working xorg.conf. glxinfo | grep -i vendor outputs: > unable to open display I have a nVidia GeForce GTX 745 with 4GB and I am using the nouveau drivers, because Nvidia's own drivers output the same error and I wanted to set my drivers back to default. This happened after I tried to install the nVidia nvidia-driver packages to have better performance.