Once you click on Partition wizard, you will receive a list of available formats like FAT, FAT32, NTFS and ISO. Choose the FAT32 option which is faster than the other two. Now click on the Save tab and give the USB device a name which will be used for partitioning. Once you click Ok, you can close the wizard and you can see your formatted thumb drive in Explorer. You can now install the petousb drivers which should be done by clicking on the driver download link which you can find on the same site.