Put Wlaunchelf on a usb device. Go to FMCB_configurator and set a E1 hotkeys to it.
For example:
- put Wle on USB device root, so mass:\BOOT.ELF
- connect the usb device to the Ps2 and set E1 R1 hotkey to it
- hold R1 while the Ps2 is booting
Then you can delete the LAUNCHELF.CNF from mc?:\SYS-CONF and create a new one.
Press SELECT on the wLE's main page, then edit the settings. From there, you can setup the File Browser back from assigning MISC/FileBrowser to any button you want.