1.download the sysinstall zip file and extract to some place.
2.insert your USB device and format to the FAT32.
3.use cmd and cd to the syslinux-3.72 directory. ex: cd C:\syslinux-3.61\win32
4.type the command: syslinux E: (E: is my usb drive location)
5.mount your ubuntu iso file.
6.copy all the file inside the dir isolinux to your USB drive.
7.goto your USB and rename files isolinux.cfg and isolinux.bin to syslinux.cfg and syslinux.bin.
8.restart your computer and set the bios to boot form USB.
9.finish.
