Boot ubuntu on External Hard drive

I want to Boot Ubuntu from my External Hard drive to use on all my computers, I'm not sure how to go about this, I currently have windows 8 and its been giving me trouble when trying to duel boot Ubuntu and Windows 8 "still haven't figured this out". Is it possible to Duel boot without too much messing around or am i better off to try to boot it from the external HDD.

 

Rather than use a large external hard drive, I load distros on USB stick.
Can your computer boot from a USB stick?

If so, download the ISO you want.
Go here: http://www.linuxliveusb.com/en/download
and download LiLi.
Install it on the USB stick and then point the installer to the linux ISO you downloaded. Be patient while it installs/writes the ISO to the USB stick.
Reboot and you should be able to boot Ubuntu.
Note, I have about 5 different distros on USB sticks. I do not have Ubuntu and I do not run Win 8.

 

you don't say what "trouble" you are having with dual boot? does ubuntu boot, but with display issues (perhaps needing a graphics driver workaround at boot)? does windows 8 boot (perhaps suggesting a GRUB issue)? does it fail to boot at all (hardware failure?)

what version of Ubuntu are you attempting to dual boot with? May I assume 12.04.2 or higher? Windows 8 devices require UEFI, which require specific UEFI-enabled linux distros (most "current" versions of "major" distros support this; Ubuntu has supported from 12.04.2 through current version)

what machine are you using? while most modern machines have fully capable linux hardware, you may have ONE component in the machine that requires a little extra effort!

why are you dual-booting in the first place? do you need both systems, or are you "trying before you're buying"? Depending on the "trouble" you're experiencing, perhaps a VirtualBox VM would be a better solution?

Regardless, if it's really what you want, You CAN boot from a usb drive. Plodr's suggestion will also work on external usb drives. However, be aware that a usb setup will have performance bottlenecks, unless you have a usb 3.0 compliant drive AND a usb 3.0 connection; also an external hard drive is typically a physical drive in an enclosure, whereas Plodr's usb stick is likely a "flash drive" with better performance.

Without additional info, we can't really recommend the best solution for you. We can only suggest the options available for your consideration.

 

Sorry for the lack of info, I have a Alienware m14x and a VERBATIM STORE 'N' GO SUPERSPEED 1TB USB 3.0 PORTABLE HARD DRIVE. I installed Ubuntu the latest version, and i can't get it to boot or do anything, Is there anyway to remove Windows 8 and replace it with ubuntu. I just really like Ubuntu as apposed to windows. I partitioned the HDD and followed instructions given to me by a friend but it still wont work at all. Even when I go to boot options ubuntu isn't there.

 

If this is your machine, you shouldn't have many problems with Ubuntu, or even Linux in general, as it is well-specced:
http://www.pcworld.com/product/1229833/alienware-m14x-14-quot-black-notebook-customizable.html

However, a few folks have noted issues with nVidia graphics (not unique to Dell or Alienware) and AlienFX, which I infer is the alien lighting scheme(?). Check these out post-installation, if you have issues:
http://askubuntu.com/questions/220576/alienware-m14x-r2-drivers

In reference to your install Ubuntu/wipe Win8 question. YES, not only can it be done, but I would recommend that! However, may I recommend the following to you, prior to actual installation?

1. Can't blame you for wanting to wipe Win8, but you DID pay a license fee for it, and you MAY want a Windows virtual machine in the future for a specific task that only Windows can do (sync a Zune media player, or Quickbooks Pro, perhaps?!). Consider making Win8 installation disks from your current system. In the future you'll be glad you have the OPTION of Win8 availability.

2. I personally recommend LTS versions as, IMO, they are more stable, have longer support cycles, and are more apt to receive bug-fix attention for those reasons. The most recent UEFI-capable LTS is version 12.04.2; please download the 64-bit version (your Alienware appears to be a 64-bit machine), available here:
http://www.ubuntu.com/download/desktop

3. Manual partition creation is "old school" and redundant to prep for Ubuntu installation; Ubuntu does this automatically during their install process. Burn to DVD or usb stick or usb drive (the ISO is too large for a CD) to create installation media, and follow this link for instructions:
https://help.ubuntu.com/community/GraphicalInstall

You should be good to go!

 

I have downloaded Ubuntu on the USB 60g thumb drive, and when the windows pops up to choose which operating system I'd like to use, i pick Ubuntu and it restarts the computer and tries to run windows 8, I've tried disabling safe boot and setting my default operating system only to get the same thing, I will try to et the error message but it was something about missing pieces or corrupt files, but it seem as though windows is trying to load both operating systems, Im going to try again and Ill post the results.

 

I'm not sure what you're talking about with "disabling safe boot" and setting your default OS?

This sounds like a UEFI and/or "secure boot" issue. UEFI is the "new" BIOS. You need to log into UEFI and disable the "secure boot" setting or disable "UEFI", thereby activiting a "legacy" boot sequence. Consult your manual to determine how to get to UEFI on Alienware machines, as each machine is a little different. I think Dell uses F8 during boot to get to BIOS, but check your machine. Disable UEFI and/or disable secure boot, THEN proceed with instructions for Ubuntu LiveCD/LiveUSB installation. See linked instructions below.