Normally our pendrive or any USB devices in FAT (file allocation table) file system, FAT16 or FAT32. NTFS (New Technology File System) is better than FAT. For more info about that, feel free to read here.
Ok now how to convert from FAT to NTFS ? This is the tutorial about how we do it. Let we start with plug in your pendrive or any USB devices with your computer. Then follow the instructions below.
1. Right click on your My Computer icon at desktop
2. Select Properties > Hardware > Device Manager
3. Select Disk drives & select your USB devices
4. Right click & select Properties (see pic below)
Done, now you can make your USB devices bootable which requires NTFS Format.