Epson Endeavor - Manual (Page 105)

If you removed one hard disk drive and are leaving another
one in the computer, you need to set the jumpers on the
remaining drive to indicate that you now have only one
hard disk drive. See the documentation that came with the
drive for the correct jumper settings.
7. If you removed a diskette drive from the lower bay and you
are leaving the bay empty or installing a hard disk drive in
it, you need to replace the front panel faceplate to cover the
bay. Secure the faceplate to the inside of the computer’s
cover with the two screws, as shown below.
3-32 Installing and Removing Drives