Open the command line (Search in the start menu for "cmd" or just run "cmd.exe")
The Following command are typed into the command line tool.
diskpart list disk select disk <your USB disk num> clean create partition primary select partition=1 active format fs=fat32 assign
Now copy the data from the images onto the USB stick and boot your system with it.
Description for each step:
Open the diskpartitioning tool <br>
List all drives<br>
Select your USB drive<br>
Delete everything and clean<br>
Creates a partition<br>
Selects the partition<br>
Sets it to active partition<br>
Format as Fat32 (same format as DVDs for example)<br>
Makes it visible in Windows Explorer