UEFI Boot issues

[phab8x]

Hi guys.
I got a problem with my Asus A55D. It uses a UEFI system.
I've installed grub and it works... I can select both Ubuntu and Windows 7... But when i click on Ubuntu it stucks and i can get in the os.. i can use CTRL+ALT+DEL to reboot.. nothing else.

I used Boot-Repair to make grub works on UEFI... I tried to "Convert from legacy to EFI" but it just doesn't work...

I installed Ubuntu from a usb drive. Then i used boot-repait to make grub works. Well.. grub works in UEFI mode..
When i installed ubuntu the screen was the purple one.. but i thought it wasn't a problem as i repaired grub...
All'inizio dell'install la schermata era quella viola...
In UEFI mode, the usbLive drive doesn't work well..
Shell says something about 'prefix'... if i try to select "try ubuntu" or "install" it stucks again...
I wanted to try to burn ubuntu on a Live CD... maybe i can solve this problem running the burned cd in UEFI mode...
Any suggestion?

Thanks :D

[oldfred]

Moved you from Yann's Boot-Repair thread, so we can deal with your specific issues.

From Boot-Repair post the link to a run of BootInfo.

Do you get grub menu? If so you may be past what Boot Repair can do and into video issues or needing other boot parameters. But post link first.