This is my first system with UEFI.... Laptop name: HP Envy 15 Notebook PC (with Touchscreen).... OS installed: Windows 10, self installed .... Processor: Intel i7-5500U @ 2.40GHz (4 CPUs) .... Ram: 8 GB .... It has Intel HD Graphics 5500 and Nvidia Geforce GTX 850M .... I created a LiveUSB of Ubuntu 15.04. md5 was fine. it worked on a friends PC. But in my laptop, I can boot from it. I select "try Ubuntu without installing" Then this happens: https://i.stack.imgur.com/8PIny.jpg Then this happens: https://i.stack.imgur.com/qf61B.jpg After this Ubuntu regular boot image starts (the purple screen with Ubuntu logo) never to move ahead.
Edit: I use the nomodeset option. Boot the LiveCD/LiveUSB .. when you get to the screen where it ask if you want to install or try Ubuntu, leave "Try Ubuntu" highlighted and hit e....... Change quiet splash --
make it end with:-
quiet splash nomodeset
nomodesetkernel parameter. When the boot options appear, highlight the one you want and then hiteto edit the options. You can addnomodesetto the kernel options line and continue the boot. This is not 100% guaranteed to work, though; it's just my initial suggestion. – Rod Smith Aug 31 '15 at 13:34