New Build Freezes / Can't Find Boot Devices

hey everyone,
im having trouble with my 2nd custom build. The first one went off without a hitch, second one is causing problems.

Specs:
Hitatchi 250Gb HDD
AMD Anthlon II x3 440 CPU (3.0GHz)
ASUS M4A89GTD PRO USB3 AMD 890GX AM3 Motherboard
OCZ 4GB DDR3 PC3-10666 Platinum Low Voltage 2x2GB
Ultra LS500 500W Power Supply
Samsung CD/RW (an old one from an old computer)
Samsung External DVD-RW

Here are my problems:
- Can't seem to find any USB Boot devices, get the message ""Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press any key"
- Can't even install an OS from a CD (eg Ubuntu which fits onto a CD). I just get to the screen and I can select once or twice then everything seems to freeze.
- Initial boot seems fine and BIOS loads fine.

any ideas on what the problem is?
Thanks for your help!
*EQL*

 

Your bios is not yet set to the boot device that you choose, go into boot section and select cd as first and hd as second, you may have to enable boot from usb. ed

 

I have my bios set correctly to boot from USB. The boot order goes:
1)USB
2)CD
3)HDD

thanks,
*EQL*

 

ok, heres an update:
Found that one of the DDR3 sticks is definitely bad. Removed it and was able to install Ubuntu since it fits onto a CD-R. After Ubuntu install I plugged in my ext DVD, and it recognized it. Restarted my computer again and the BIOS detected the Ext DVD! Set the ext DVD to the primary boot device and success! I am in the process of installing Win7! Woot! Unfortunately I have to exchange my DDR3 sticks, but at least now I know that my system DOES work! YAY!
*EQL*