Comment 33 for bug 1090829

Hello,
I had the problem to with an HP Pavilion g7-2242sf.

I solved it with trials and error, and inspecting what was going on in the files, etc...
At the end, I roughly did the same as the work around you provide.
see : http://ubuntuforums.org/showthread.php?p=12491984#post12491984

May be these elements may help :

When starting the machine, I click ESC to have the boot options, then F9 to go to "Boot Device Options".
There, you get : "Boot Menu Option", with several ways to start :
 - OS boot Manager
 - Ubuntu (TOSHIBA MQ.... the disk refence...)
 - Boot from EFI file...
 - Notebook Hard Drive
 - Internal CD/DVD ROM Drive

When going to the "Boot from EFI file..." option, you get a screen, with capability to navigate in the EFI partition (a File Explorer), and select the folders and files (efi files).
It is a kind of Dos File Explorer, navigation in the folder (like in the old days...).
There, when you go to the EFI folder (root folder), then you find the folders for "boot", for "Windows", for "HP" (recovery) etc.... and the one for "Ubuntu".
In the Ubuntu folder, you find the grubx64.efi file.

Before the workaroud (and strugglin), when selecting this file (select highlight in the list, and click Enter), then I was getting the same "navigation screen", but with nothing proposed in it.
As if I was entering a sub folder, but there is nothing in it, not even the "." and ".." lines of the usual minimum directory listing.
The file is corrupted, and the selection+ENTER does not trigger the launching, it only propose a corrupted navigation, so a kind of Folder presentation, but with really nothing in it.
The only way to get out is shut down the pc.

After the workaroud and with a proper grubx64.efi, when selecting the file and clicking Enter, the Grub start, and propose the list of OS to choose for booting.
Normal behavior.

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IMHO : I don't think that the whole partition is corrupted, or read only.
I think that only the grubx64.efi file is corrupted.
I think that something goes wrong when Ubuntu do the installation, ... and then the grubx64.efi file is left "as is", ... even if the installation process continues and says it is ok.

why :
if the the whole partition is corrupted : the computer should not be able to start with the Windows 8 boot.
if the whole partition is read only : then the process of installation of Ubuntu should not be able to create the grubx64.efi file (not even an empty file with 0 octet).

The file was written, ... but it cannot be used properly by the EFI process because it is incompleted or corrupted.

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Why the grubx64.efi file is not correctly set ?
I don't know.
I did the process of installation of Ubuntu twice (may be 3 times) : each time, the same result.
But I did not notice anything usefull when Ubuntu was installing.