What I have done in the past is set the CD drive as the only boot device. Disable all other boot options.
This has forced the BIOS to only boot from the CD drive and not seek out any other available boot options.
Also, on my motherboard, I have a second page with boot options and my CD / DVD drive is selected there, although there is a CD drive option on the first. The drives actually show the manufacturer name.
If you try this method and it works, remember when the Windows install does it's first boot after copying the files over, to go straight into the BIOS before it boots up and include the HDD in the options again otherwise your PC will continue to boot from the CD and loop install.