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I'm trying to install Ubuntu 12.04 to run in VirtualBox alongside my Win7 64bit OS, without having to dual-boot.

I added the 64-bit Ubuntu iso to my VM, and powered it up so to proceed with the installation, but it prompted me with this error:

This kernel requires an x86-64 CPU, but only detected an i686 CPU. Unable to boot - please use a kernel appropriate for your CPU.

Why does it give me this error, seeing as I have a 64bit processor? Is there a way that I can run Ubuntu via my VM in the first place?

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marked as duplicate by minerz029, karel, Avinash Raj, Eric Carvalho, BuZZ-dEE Jan 8 '14 at 11:18

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

The Ubuntu in the VM is looking at a virtual CPU. You have to change the setting in VirtualBox when you create the VM. – user68186 May 6 '13 at 20:18
up vote 2 down vote accepted

When creating a VM using VirtualBox, the first screen you are presented with asks for the name of your new VM and attempts to auto-detect which operating system you're installing. Make sure that you select Ubuntu (64 bit) in the OS drop-down menu. Just selecting Ubuntu in that menu will result in the error you have described.

Screenshot of 64 bit VM selection

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Thanks for your help; selecting the 64bit version of Ubuntu definitely helped to solve a couple of issues. Now I must enable VT-x/AMD-V in BIOS. Thanks again :) – neo May 6 '13 at 22:08
In VirtualBox, those are under (right click on VM)->Settings->System-> Acceleration. Glad I could help. :) – dfarrell07 May 6 '13 at 22:14

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