I'm looking at http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows
it's a really long time since I've used linux, but to me this is unclear, I've downloaded the app from Pen Drive Linux, but then when I use it, in step two it says "Click 'Browse' and open the downloaded ISO file." but at no point has it told me to download an iso file, or given a link to where I download it from.
The one given in the picture is called precise-desktop.iso, I've no idea if that's the file I'm supposed to be downloading, or if I need to rename the file to this, or if I just need to download a regular ubuntu distribution, which is what I'm doing now.