Windows 7: Computer won't boot from disc drive

hello

I am trying to run memtest on a new build and for some reason, the machine will not boot from the disc drive. I'm positive that it CAN boot from the disc drive because I just installed windows 7x64 on it last night. I have already configured the BIOS to boot from CDROM as it's first choice and selected to boot from CDROM thru the boot menu. I am 100% positive that this memtest disc is good because I just successfully ran it on my main machine with no problems. What do I do? Thanks for your help in advance!

-RW

ps. to power the disc drive I am using a 4-pin molex to SATA adapter since my PSU only has 2 SATA pwr connectors and they are being used to power my 2 HDD's. I don't know if this has to do with it...could it be a bad adapter not powering the drive at initial startup? Bear in mind that the drive works fine once I'm in the OS.

If you were able to boot from a DVD recently, its probably the DVD. Try again.

Guide to using Memtest86+ - Geeks to Go Forums

Did you download the .iso file of Memtest86 to burn a bootable CD ?

Memtest86.com - Memory Diagnostic

I have tried a different disc and nothing is working. I'm sure the disc is good because it boots and runs like a champ on my other PC.

Run windows Memory Diagnostic from Windows when you start the machine and you are in windows, it will give to the choice to restart, and it will do it "Run" the next time you start your machine,I think you will have to go back into your Bios and tell it to boot from your harddrive first by the sounds of what your saying.

well I wasn't able to figure out what the issue was, but in the meantime I ran Memtest from an bootable usb drive with no problem. I'm still very curious as to why it would not run from the disc drive on this new build, but it will on my other machine....oh well.