Boot up a live usb and try to repair the bootloader with these commands:
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install boot-repair
After installing 'boot-repair' launch this program from dash by searching for the term and click its icon to launch it.
If this doesn't work then boot into Windows 7, download and install a freeware called 'EasyBCD' (latest version is 2.2)
After installing this tool, select 'add new entry' column and install grub under the Linux tab.
Sorry I'm on my phone now so I can't add links and pictures to the post. I'll surely edit this post today when I get to the house
Hope this helps.
First, you probably can disable Secure Boot; you just haven't figured out how. For systems that shipped with Windows 8, Microsoft required that users be able to disable Secure Boot, so if it really can't be done, Acer is in violation of their contract with Microsoft. That said, the option could be completely hidden or named in a confusing way. That said, disabling Secure Boot should not be necessary -- it does work for you, or you wouldn't have been able to boot the installer. There is one exception, though....
In the bcdedit
command you said you used, specifying grubx64.efi
bypasses Shim, which is what Ubuntu uses to deal with Secure Boot. Thus, that particular command will work only if Secure Boot is disabled. The equivalent that should work with Secure Boot active is:
bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi
You can also try using EasyUEFI in Windows. This is a third-party GUI tool for managing EFI boot manager entries. Try moving the working ubuntu
entry to the top of the priority list.
If that doesn't work, then chances are your firmware is defective. I'd say to return the computer to the store for a refund, but if you've had it for beyond the return period, you may be out of luck on that score. There is an ugly hack of a workaround, as described here (among other places). At a minimum, if you need to resort to this "solution," you should write to the manufacturer. If possible, return the computer for a refund because it's defective.
Best Answer
Temporary Solution
When you start your pc keep
Left Shift
pressed. it will show you the grubPermanent solution
If you get to start ubuntu by the temp soln then to make boot permanently show the grub-
Open startup manager(install it if it isnt installed from sofware center)
Change the value for timeout- pref 5 - 10 secs
Default OS - Whatever you want
Rest leave everything as it(you can edit that if you want to)
if that does not work install
boot-repair
via ppaThis worked for me should work for you too