It is likely to depend on the speed of the external hard drive, although most newer external hard drives have a reasonable speed, so it is likely you will be fine wi th using an external hard drive.
Yes you can, when the computer is booting up open the boot menu and choose the external as your boot device, i have a external hard drive with Ubuntu on it and do exactly that, I'm sure it can work with windows.
Get unetbootin from ubuntu's website. Select the ISO from your hard drive then reboot and boot from USB! Voila!
Do you mean, install Ubuntu and not enter the BIOS? To install Ubuntu using a CD, you need to enter the BIOS, setting the CD drive as the first boot. Otherwise, the computer will still boot off the hard-drive and ignore Ubuntu on the CD drive. If you meant, install Ubuntu without removing your Windows operating system? Then you need to set up a dual-boot between Windows and Ubuntu. Search the internet for fuller instructions on creating a dual-boot. If you simply want to try using Ubuntu without making any changes to the OS already on the hard-drive, either use the CD containing Ubuntu as an ISO file, known as a Live CD. Or, look up WUBI on the internet. Wubi will allow you to download and use Ubuntu as you would any other Windows file - without making any changes to the hard-drive.
To boot from a DVD in Ubuntu, first, insert the DVD into your optical drive. Restart your computer and access the BIOS/UEFI settings (usually by pressing a key like F2, F12, ESC, or DEL during startup). In the boot menu, set the DVD drive as the primary boot device. Save the changes and exit, and your computer should boot from the DVD.
I do mean an external hard drive.
Your Bios has an option to boot from your DVD Drive or external drive. If the internal or external drive has no boot sector or disc with a boot sector the system will not boot. You will need to go into your bios at boot time most often by tapping your delete key or whatever option your motherboard bios requires and change the option back to boot from your hard drive.
When you choose the installation partition to install on, choose your flash drive then on startup, hold the option key down, it should show you your flash drive partition to boot up with.
If you get a message in Ubuntu stating "Still waiting for root device" and you HAVE installed Ubuntu while an external sata hard drive was attached or an extra sata drive that was removed later. Check the GRUB file! You might need to boot into Ubuntu with live CD and change /boot/grub/grub.cfg on the boot drive. The grub.cfg file is where to change the root drive device settings. Change from /dev/??sdb1?? to what your root drive is. usually /dev/sda1THIS IS ONLY FOR NEW UBUNTU USERS THAT INSTALLED UBUNTU WITH A REMOVABLE SATA DRIVE ATTACHED TO THE COMPUTER DURING INSTALLATION. OR FOR PEOPLE THAT KNOW THEIR BOOT DRIVE IS NOT WHERE ROOT IS TRYING TO LOAD.If you are not one of these users then just Google all the other fixes. Most answers say "It can not be the GRUB device settings", but it is sometimes.More Answers:There are several possible ways that error could occur. The most likely reason is that the file system or hard drive has become damaged in some fashion. Booting in recovery mode should offer more detail as to the cause of the error, as well as providing the opportunity to run fsck if the file system is damaged.
Only if you can boot from it. Most new computers can boot from a USB drive, but older ones may not be able to.
I would suggest installing windows on one hard drive, then installing ubuntu on the same hard drive. Use the other hard drive for the backups (partition it).
When you first install Ubuntu, it will walk you through the steps to install it and keep your other OS installed. Then when you boot your dual-boot system, you can simply select Ubuntu.
The GRUB bootloader gets it's menu off of the Ubuntu partition. Since you deleted the Ubuntu partition, it can't read the list or know what to do next. You have two options:1. Reinstall Ubuntu.2. Boot from the Window XP CD, access the Recovery Console, and runfdisk /mbrThis will rewrite the Master Boot Record, and shouldallow you to boot back into Windows.