I can't tell you why Unetbootin isn't working. Never used it.
Your last post, you're talking about a dual boot. Yes, it's very easy. The first thing you want to do is install Windows.
Then, you reboot with your thumbdrive plugged in. It will load Ubuntu's live disk/install up. Click install and it gives you a few options. I think they are "Use Entire Disk", "Install Side By Side" and "Advanced".
You want to choose "Install Side By Side". There is a slider there that will allow you to set your partition sizes. If you're going to use Windows more, give it more room...
Then you go through a fairly easy to understand install series of pages. Setting up your account, passwords, time zone...
When you reboot, it will pop up with GRUB. GRUB is the boot manager. Select Linux for Linux and Windows for Windows.