Recently I am facing a great trouble . My Laptop : HP Probook 440 G3 Core i5 6th Gen 1TB HDD 4GB RAM 14" laptop I installed Ubuntu 18.04 ,19.04 or 19.10 a lot of time (dual boot). I can go with the distro easily 1 or 2 days minimum.Then when I am gonna boot then after sometime it always stuck with pre-log in mode picture with ubuntu sign. I don't understand what to do. I am really very eager to learn about Linux OS . Please help me.