Failure to boot from CD/DVD

Hello, first time poster here.

I've run into a very peculiar problem today trying to install windows onto my newly built PC.

The specs I am running are:

Core 2 Duo 3.0ghz
Gigabyte GA-X48-DS5 motherboard
4gb (2x2) Corsair XMS memory
SONY DVD-RW drive

I go into my BIOS, set the first boot device to CDROM, save my settings and let it start loading. It gets past the initial post screen then says Verifying DMI or something or that other than it says:

Boot from CD/DVD: (and it just basically hangs right here, still blinking where the cursor is)

Occasionally if I mess with enough settings or try my backup WinXP/Vista CD it gives me these two errors:

CDBOOT: Memory Overflow Error
CDBOOT: Couldn't find NTLDR

TL;DR: My three problems are:

Boot from CD/DVD: (and it just basically hangs right here, still blinking where the cursor is)
or
CDBOOT: Memory Overflow Error
or
CDBOOT: Couldn't find NTLDR


What could the cause of my problem(s) be? Defective DVD-drive? Wrong connections somewhere?