I was running Windows 10 64 bit. I downloaded the installer from Lubuntu.me downloads page. I can run fine from the USB. I installed it and chose erase disk, I tried both Swap and No Swap. Both times bootable device not found. I tried turning off secure boot. Still bootable device not found.
I think I have to do something like this but all the instructions I find are for ubuntu. And at the moment I have a dev/sda which is the live USB and dev/sdb with a 1/2 on it when i looked at gparted.
If you’re trying to download an earlier release; the manual link I gave you is incorrect (eg. change the word “stable” in the URL to “lts” to read the manual for 20.04 LTS)
In the manual you’ll find this image which provide details that BIOS is being used (read top left) and towards the bottom where the boot loader was being written (ie. MBR on vda or /dev/vda for the picture I’m referring to in the current stable or 21.10 manual). Did those values match your system?
If I’m reading that output correctly, it’s saying it couldn’t find the package in that repo you tried to install or use. I haven’t worked with boot-repair myself so I am unsure how that goes about.
When you did the manual partition install, did it boot normally after that or did it fail? The scheme you setup as shown in the picture for the manual partition install looked alright to me.
Please do not use Boot Repair, unless you don’t mind that it is worse afterwards.
Please make sure, that you have the latest firmware (UEFI) installed (from Windows).
I am quite sure, that the bootloader is installed correctly and any “repair” of the bootloader is not necessary. The Acer firmware is often a bit special.
One of the known ways is:
Enter the firmware settings
Go to “Security”
“Set Supervisor Password” (and remember it)
Save and exit
Reenter the firmware settings
Go to “Boot” or “Security”
Select “EFI File”
“Select an UEFI file as trusted for executing” (navigate to “HDD…” > “EFI” > “ubuntu” and choose “shimx64.efi”
Enter a name for it (e.g. “Ubuntu”)
Save and exit
Maybe your firmware is different. Then we can try to use an old USB stick, which is then loading the installed Lubuntu. For that, please show the entire input and output from the terminal: