A couple of days ago I decided to install Ubuntu 14.04 LTS on my Windows 8.1 Pro with Media Center (with update 1). I decided to run Ubuntu from a USB stick. I did the followings:
1.I took a USB stick of 4 GB and formatted that (FAT 32). You need at least 2GB of free space into your PC.
2.I downloaded UNetbootin. UNetbootin allows you to create bootable Live USB drives for Ubuntu, Fedora, and other Linux distributions without burning a CD. It runs on Windows also.
3.I already downloaded the ISO image of Ubuntu 14.04 LTS (64 Bit)
4.Next I inserted the FAT 32 formatted USB stick in to the USB port.
5.I executed UNetbootin installer.
6.I selected Ubuntu 14.04 Live from the drop down menu under the Distribution.Also selected ISO image and selected the exact location of the ISO file which I downloaded earlier.
7.It started extracting and copying files.
8.Once done it installed the bootloader and finally rebooted.
9.During booting I opted to boot from USB .
10. From the list of menus select Try Ubuntu without installing….Press the Enter Key.