FS Toolbox is a DANGEROUS program, only use it if you have the knowledge of the wii ! I advise you guys that use this program to install Bootmii as boot2 ! FS Toolbox is a NAND browser that can dump files from the nand to sd card and write files from sd card to the nand,with this you can edit files on the nand to test stuff out and to have backups of your files if something ever goes wrong