No Valid CD-ROM device drivers selected

When installing new hardware, I received a Windows Protection error at startup. I rebooted to the command prompt to enter the command “mscdex.exe /s /v /d:mscd001”, because my CDROM drive(D:) was not being recognized, and I could only run in Safe Mode. The error I received, is “No valid CDROM device drivers selected” when I used this command from C:\Windows\Command. How do I fix this? The hardware I was installing at the time this error happened was a CD-RW drive from Iomega as a Slave to the CD-ROM already there, sharing the same cable to the secondary IDE slot.