If you want to completely remove Rockbox for some reason, simply delete the rockbox.iriver file and .rockbox directory from your player. This way, the bootloader will automatically boot the iriver firmware. However, it is a good idea to keep the Rockbox bootloader, even if you are not using Rockbox. Unlike the iriver firmware, the Rockbox bootloader allows you to boot into USB mode even if the hard drive is corrupted. (The iriver firmware, on the hand, will not enter USB mode until it has successfully read the hard drive.) Thus, the Rockbox bootloader provides the possibility to rescue a broken file system or hard drive in situations that would render your player unbootable without it.