Here’s the thing with Dell motherboards that support sata + pata drives. Zeroshell will have issues loading up from the CD boot loader with the default unattended install.
To my understanding it’s a motherboard chipset issue on the Dells since it’s the only ones I’ve ever come across with this problem.
The easiest way to resolve this since I don’t really see how zeroshell can take advantage of the super fast i/o of the pata/sata drives is to just go into the BIOS and under advanced options for the hard drive controller look for the options which are different on many models but go as follows:
PATA + SATA
Choose the IDE one or the legacy one. Then reboot and zeroshell will install as per usual.