P5 Firmware

Have 2 P5 regenerator.Trying to upgrade firmware.Download latest firmware to desktop.Unzip files into new folder desktop.Use 2 gb SD card.Erased and formatted to FAT.Drag unzipped files to SD card.SD card shows 6 files.Turn power off on P5 insert SD card Turn power back on.Firmware will not load? Any permissions that I have to change on SD card.Different format ? Need help.Thanks