The Ubuntu Live CD isn’t just useful for trying out Ubuntu before you install it, you can also use it to maintain and repair your Windows PC. Even if you have no intention of installing Linux, every Windows user should have a bootable Ubuntu USB drive on hand in case something goes wrong in Windows.
Creating a bootable USB flash drive is surprisingly easy with a small self-contained application called UNetbootin. It will even download Ubuntu for you!
Note: Ubuntu will take up approximately 700 MB on your flash drive, so choose a flash drive with at least 1 GB of free space, formatted as FAT32. This process should not remove any existing files on the flash drive, but to be safe you should backup the files on your flash drive.
Put Ubuntu on your flash drive
UNetbootin doesn’t require installation; just download the application and run it.
Select Ubuntu from the Distribution drop-down box, then 9.10_Live from the Version drop-down box. If you have a 64-bit machine, then select 9.10_Live_x64 for the Version.
At the bottom of the screen, select the drive letter that corresponds to the USB drive that you want to put Ubuntu on. If you select USB Drive in the Type drop-down box, the only drive letters available will be USB flash drives.
Click OK and UNetbootin will start doing its thing. First it will download the Ubuntu Live CD.
Then, it will copy the files from the Ubuntu Live CD to your flash drive.
The amount of time it takes will vary depending on your Internet speed, an when it’s done, click on Exit. You’re not planning on installing Ubuntu right now, so there’s no need to reboot.
You’re now ready to boot your computer into Ubuntu 9.10!
How to boot into Ubuntu
When the time comes that you have to boot into Ubuntu, or if you just want to test and make sure that your flash drive works properly, you will have to set your computer to boot off of the flash drive.