I have been struggling to install Ubuntu on my HP desktop PC for a while. The specs of my system are: HP 500-314 PC with Nvidia GTX 750 Ti.
My intention was to install Ubuntu side-by-side with Windows, but without adding a bootloader to the Windows partition. So I wanted to install Ubuntu on a separate HDD and choose the second HDD from the BIOS boot options.
My attempts to install Ubuntu using version 14.04 or 15.04 were not successful because after installation the video driver was not loading correctly. I found out later that this was due to my Nvidia video card.
Ubuntu 15.10 has solved this problem to some extent, such that now at least the login screen is shown correctly and you can login and launch Ubuntu. There are still some corruptions of the screen, but it is workable.
To fix the screen corruption, the Nvidia driver needs to be installed. The following commands needs to be executed to install the Nvidia driver from the external repository. I have installed the version 352 driver as that works fine with my GTX 750 Ti.
sudo add-apt-repository ppa:graphics-drivers/ppa sudo apt-get update sudo apt-get install nvidia-352 nvidia-settings