Help please- Win 7 Need Driver Sony SXRD KDS - No HDMI or Sound

I am having a problem with a new Win 7 build and have tried everything I could think of without success; hoping someone has a solution.

Background:
I installed the OS with the HDD set to Native IDE, the system automatically loaded a driver that worked with my 50" TV and sound played just fine through the TV speakers. After the fact, I realized I had failed to configure the SATA HDD for RAID AHCI and so changed the HDD setting in the BIOS and reinstalled Windows as a new system build. It failed due to the lack of a driver, and Windows being ever so "helpful", tried to fix the issue which it could not. After investigation, realized that the correct driver had to be manually loaded from a disc, so I wiped the harddrive clean, cleared the CMOS and started over again.

Problem:
The HDD and OS loaded just fine, but Win7 selected a "generic PnP monitor" driver, does not realize the HDMI connection and there is now no sound. Manually changing the setting to a 1920X1080 monitor does not make a difference nor does deleting the existing driver, selecting other model Sony drivers, or reloading the OS.

I have spent hours trying to find a driver for the Sony SXRD (any model) with no luck. I have also tried everything I could think of to return the system to it's initial state hoping that Win 7 might reload and recognize the HMDI connection / provide sound.

Welcome any suggestions you may have. What is so bizarre is that there was an appropriate driver when Win booted for the first time but it is nowhere to be found in the application. (The list of choices does not include anything similar and Realtek HDMI Audio shows that it is "not plugged in".)

Look forward to any suggestions / assistance. Thank you.

System specs:
Monitor- Sony SXRD KDS-50A3000
AMD X3 720
Mother Board- GA-MA785GPMT-UD2H
Win 7 Professional
DDR3 1333 2X2 10666CL8D G Skill Memory
Hitachi 640 GB HDD
DVD/CD Burner
Corsair 650 PSU