Hi.I have a Dell latitude D630.long story short...linux was recently installed which being computer iliterate has obviously cause myself problems! I currently have a usb fash with windows 8.1 already installed onto it!is there anyway I can just erase EVERYTHING ON THE LAPTOP AND START FRESH AND THEN INSTALL WINDOWS 8.1 ALMOST AS IF IT BRAND-NEW STARTING FROM ALL THE factory DEFAULT SETTINGS OR SOMETHING!at this moment I'm getting stuck at the screen which type of installation do I want (upgrade or custom) tried both and still can't get it to work!PLEASE HELP!!!!