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Am trying to boot Ubuntu 12.04 using DUET. I have bootable DUET in one USB flash drive and i have bootable Ubuntu 12.04 in another USB flash drive. After getting into DUET,Through Boot Maintenance Manager,i have selected EFI/boot/bootx64.efi and am getting GRUB command prompt. How do i boot ubuntu using this command prompt now? when i try root command means it is throwing "out of memory" error Can you please help me on this?

Note:I have Windows XP and Ubuntu 32bit on my PC.that's why i would like to try "TRY UBUNTU WITHOUT INSTALLING" from USB flash drive

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Can you provide more details about the physical computer, such as RAM, processor, make/model, etc. – Taegost Aug 14 '13 at 14:05

This is a GRUB problem, not a DUET problem. (DUET seems to be working correctly, based on the description.) It sounds like GRUB isn't finding its configuration file, which is odd if this is a standard Ubuntu installation with its usual version of GRUB; but if you did anything unusual to isntall GRUB, it could be you need to re-visit the GRUB installation options. Also, Ubuntu normally installs GRUB to the ESP's EFI\ubuntu\grubx64.efi. Thus, you might try launching that file rather than EFI\boot\bootx64.efi. The two files might actually be identical, but if they're not, using EFI\ubuntu\grubx64.efi might work better.

Unfortunately, GRUB is very tricky to configure correctly. It works easily for many users only because most distributions include complex scripts that scan the system and create a configuration that works correctly. Instead of working on GRUB, you might consider using another EFI boot loader. My Web page on this topic covers the options. The easiest to get started with is likely to be my rEFInd boot manager in conjunction with the EFI stub loader (which is built into 3.3.0 and later kernels). If you're using the original Ubuntu 12.04, it came with a 3.2.0 kernel, so the EFI stub loader won't work; but the 12.04.2 update comes with a later kernel that does have EFI stub loader support.

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Hi RodSmith,Thanks for your reply.Am not trying to Install GRUB and i can see bootx64.efi and grubx64.efi under EFI\boot path.Am using 12.04.2 only..As you mentioned i shall try use rEFInd boot manager with EFI stub loader and let you know the feedback – SenthilKumar Aug 16 '13 at 6:33
Hi RodSmith,can i use Ubuntu 32bit OS(12.04.02 32bit) to Install rEFInd boot manager or Is it mandatory to have 64bit OS(12.04.02 64bit) only? – SenthilKumar Aug 16 '13 at 11:41
If you're installing the boot program as EFI/BOOT/bootx64.efi on the ESP, then you can use anything -- 32-bit, 64-bit, or even a foreign architecture like PowerPC. You need to match the architecture if you register the boot loader with the EFI via efibootmgr, bcfg, or similar tools, though. My experience with DUET is that these tools don't work -- or more precisely, their effects disappear when you reboot. Thus, you'll need to store your boot program as EFI/BOOT/bootx64.efi. – Rod Smith Aug 17 '13 at 17:23
Thanks for your reply Rod Smith – SenthilKumar Aug 20 '13 at 11:35

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