A quick guide to make an USB Flash Drive bootable. This is usefull if you use Microsoft Windows installation images.
Open Command Prompt as an Administrator and go to town with these command steps:
diskpart list disk (note the drive number of the USB flash drive) select disk "drive number" clean create part pri - NOTE: if flash drive is larger than 32Gb use size=32000 or 16000 to limit size of partition for FAT32 file system select part 1 format fs=fat32 quick active exit
Now the USB flash drive is ready for a Windows installation image