i tried installing the latest ubuntu 18.04.1 LTS on an older dell optiplex 330 desktop that i have. I downloaded ubuntu from my laptop and used rufus to load it to a usd drive. I then installed it to my desktop with out problem until it restarted, it loaded and froze at the ubuntu load window. The mouse is frozen but i still have keyboard function. Not sure how to trouble shoot this. Any help would be appreciated.