Hello Cberwood, I am an HP Support Engineer. I am speaking for myself and not for HP but I believe that I can assist you.
I misread your original post, I read "Install an EIO Hard Disk" as if you installed one not that it was part of the device display message. DavidZuts is correct, on some older Color LaserJet printers Mopy will be enabled by default with UPD because they meet the minimum memory threshold. Unfortunately for these older color devices the minimum is too low and the printer may display "unable to store job" when multiple copies are printed. The fix is to disable Mopier Mode in the driver.