Do you have access to another computer?
Here's a procedure I have used. I booted the CD and installed to a USB drive (a 2.5inch notebook drive in a USB caddy) which I then connected to the computer on which I actually wanted to run pfSense. I had to configure the BIOS to boot off a "USB Hard Disk" and now it works fine. This sort of thing may get you past the "CD problem". Once you have the software installed you probably won't need to use the CD again for a good while.)
There are a number of variants, for example:
install to a hard drive on the other computer then move the hard drive to the computer on which you had the trouble.
install to a USB flash drive, take it to the real target computer, boot it then copy (dd) the USB flash drive to the hard drive on the target computer