Required CD/DVD Drive Device Missing - Fresh Install  

Good Afternoon Everyone

I am having a hell of a time here working on a customers computer. Just got all the parts to do a new build for him, and have run into an issue when trying to install Win 7 Ultimate x64. I get the "A required CD/DVD drive device driver is missing."

Specs:
-MSI 880GMA-E35 Motherboard
-AMD Athlon II X4 Processor
-4GB Ram (2x2GB)
-500GB Seagate HDD (Brand New) (SATA)
-Sony Optiarc AD-7260S DVD-RW Drive (SATA)

I've reviewed other posts of this nature, and tried the following things:
1. Checked the SHA-1 HASH values with the official list, which checked out.
2. Attempted install via Bootable USB thumbdrive (With and without DVD Drive connected, to no avail)
3. Removed all but 2gb of RAM
4. Attempted to load any drivers from the Motherboard disc, to no avail, the program wouldn't run.
5. And of course, tried to install it normally using the DVD

Im at a loss here... any ideas?

-Z-

Is the CD drive recognised in the Bios?

I too have a nasty feeling that the motherboard could have been defective in the first instance or could have become defective due to improper handling/assembly. (Remember electrostatic).The only way to confirm is to check whether the bios is OK in all repects. The set to default and check should confirm this. He should also reset the CMOS as per the procedure outlined in the manual. So first thing first.:)

So. As a last ditch effort out of pure frustration and lack of time, I downloaded a Windows 7 Ultimate x64 ISO from the internet, and burned a new disk. Viola. Problem fixed. Seems the factory disk was buggered somehow even though the HASH matched and everything. Appreciate all the feedback, and its good to know that. To answer your questions for good measure however:
@Golden: Retail straight from Windows
@Karl: Did that shortly after I posted to make sure I hadn't herp'd my derp on something. (Not that it mattered anyway, but it was all in properly)
@Jumanji: That was my fear as well, especially when the CMOS reset didn't help. Luckily the BIOS looked perfectly fine, hence part of the confusion. (P.S. Electrostatic straps ftw to prevent that crap from happening.)

Once again thank you all, and thank god for .ISO's being downloadable for cases like this where you've got nothing else to try.

Hmmmm............ whoever would have thought that the original factory disk could be corrupt. You deserve all credit for downloading the ISO and trying without losing hope. I can understand the frustration you would have gone through. Anyway good to know that your motherboard is perfectly OK and you take all necessary precautions like electrostatic wrist straps etc. You may sleep well now.:). Cheers.