i tried installing ubuntu 13.04 on my hp pavilion g6 notebook which came with windows8 pre-installed. i tried it with a DVD and choose "erase everything and install ubuntu" afer installation when i reboot my pc it did not load ubuntu instead shown a screen like "boot image did not authenticate press entre to continue" on pressing entre it shut off every time. i tried abd tried installing it but it did not work. so please help me how to fix this error.....
The problem is related to secure-boot. Here is what you need to do:
This error indicates that it is related to Secure Boot which is a new security feature with Windows 8. Once you disable Secure Boot, hopeful the problem will go away.