I was wondering if anybody could help me with a issue I'm having.

I bought Fallout: New Vegas Ultimate Edition the day before yesterday. I promptly installed it via Steam and when finished (100% finished, including DLC and updates), started it up.

Launcher loaded up, everything is cool. Recognized my computer as having "Medium" graphics quality (I was expecting Low). Everything still cool. Launcher has sound, nothing is distorted, everything is immediately responsive. I hit Play. The first screen comes up, sound good, picture quality immaculate. Second screen, Bethesda Logo, then crash.

This program stopped running. No reason for it. Nothing in the way.
It says something like "Fallout: New Vegas has stopped working."

I know of issues regarding Fallout games on steam, so I went through a list of fixes:

1) I have AVG Antivirus disabled. And have had it disabled the entire time. For a short while I had it uninstalled, but no change.
2) I have verified cache multiple times. First is said there is one file missing and it will be reacquired. After changing compatibilities a few times, it started saying there are two items missing and they will be reacquired.
3) Am running as Administrator and have "Always run as Administrator" checked.
4) Have disabled the Steam Community in-game option.
5) Moved Steam from program files folder to the C: Drive. (As in no longer in program files, but its own folder on the C: drive. This is how I got Oblivion to work in Vista.)
6) Have deleted the Steam appcache folder and restarted my computer multiple times.
7) Have attempted to download d3d9.dll (or whatever it is called) via NexusModManager.
8) Have updated my system, directX, and various other drivers in a last attempt at figuring out what is going on. (All of them were up to date as far as I can tell)
9) Have scoured the internet and Steam forums for any advice, suggestion, fixes, or help. Have not found anything that made progress.
10) After running on XP Service Pack 3 as Administrator, Fallout NV started not running at all after hitting Play on the Launcher. Now it says "Failed to start the game. (app already running)". however when I uninstalled Nexus ModManager, this went away.

I'm obviously very upset. I've scoured the internet, Steam forums, and here. I didn't find anything of use to me.

PLEASE help me.

I'm running Window 7 32-bit with a computer that can handle Borderlands GOTY edition (currently uninstalled), Skyrim with a LOT of mods, World of Warcraft: Mists of Pandaria (while also surfing the internet), Portal 1 and 2 (currently uninstalled).
I'm running a Intel Core 2 Quad with 4GB Ram. (Not the best, but my old computer fried and my computer guy spliced this computer and parts from my old computer for little to nothing.) I meet the minimum system requirements.

I consider myself somewhat handy with computers, but I do not claim to be a genious. This problem has my totally lost.

-Dz