The K2000 derives its 1-199 sounds from internal ROM so they're not gone, just temporarily overwritten. Simply hard reset your Kurzweil and they will come back. Note: this will erase all sequences, setups, custom programs, samples, and settings, so make sure anything you want to keep is backed up on hard or floppy disk. Go to Master and choose Reset, Yes, and it will bring everything back to factory defaults.