1) go to the KORG website and get the latest OS
(the current OS is 3 discs long)
2) power the unit off
3) hold down the ENTER and LOCATE button
4) power the unit back on
5) this brings you to a diagnostic screen
6) it will say please insert disk 1
7) load the disk and hit enter
8) after it is done it will ask you for disk 2 and disk 3 accordingly
9) when finished, reboot the keyboard and viola!