Common Display Freezes

(I'm not sure if this is a driver issue, a hardware issue, or some sort of foul black magic. Admins, feel free to move the thread to wherever it fits.)

The title pretty much sums it up. Launching certain programs and opening certain interfaces seems to cause my entire screen to just stop. It usually just looks like a bit of lag that'll pass, but it never does. My computer will still whir and whee when I hit keys, and my audio will keep playing for a few minutes or so before it cuts off.
I've already dusted out everything, cleaned up my heat sink, and installed the latest drivers I could find. Here's my basic system specs:
- Vista Home Premium 32 bit OS
- nVidia GeForce 8800 GT graphics card
- 3 GB RAM
- AMD Phenom 9600 Quad Core Processpr, ~2.3 GHz

If you need anything else, just ask. These are the instances I can think of off-hand when I try to do something and it freezes:
- Launching Mafia 2, Terraria, or Amnesia on Steam (These all used to run)
- Attempting to open a file in Synthesia through Windows Explorer
- Rotating too much or around a certain object in Google Sketchup
- Any video calls or incoming video via Skype
- Turning on my webcam seems to freeze it every now and then

I've tried isolating the problem, but I can't seem to get anywhere on it. Any help is appreciated, and I'll try to make sure I reply ASAP.

 

I don't think it's security, I've only got one antivirus/firewall in use (Comodo Internet Security). Booted in Safe Mode, and nothing graphics-intensive or anything using OpenAL worked. Just gave me a generic "Insufficient device found" or "No device found" error message.
As for yellow !'s, I've found one under-
Network Adapters/Virtuabox Bridged Networking Driver Miniport #3
Other devices/Multimedia Video Controller
No red X's, though.

 

Time for a whimsical update!
I think it's Steam that's the culprit. Everything else runs fine when Steam isn't running. Synthesia+Windows Explorer is fine on its own. Certain things just appear to not want to run well with Steam. Including quite a few Steam games. Bummer.

 

Sorry for the bumps, I'm not sure if I can edit posts or not.
Anyways, disregard my last post, turns out I was wrong. Synthesia crashes if a window is on top of it. Steam's little "FRIEND PLAYING GAME" popups were doing this in Synthesia, so I figure that was the problem. But placing any window, even browsing for files through Synthesia, seems to freeze everything up.
Back to square 1.

 

Oracle Virtualbox. It's uninstalled, and I tried to update my nVidia drivers from a hyperlink from a Steam game. That made everything worse. I've uninstalled all of the nVidia software, and all I have now is the basic stuff from my graphics card. Nothing really runs except for very basic programs, and definitely nothing that would freeze my display. I think I've narrowed it down to my graphics drivers, not a random startup application. Now for my safari through the nVidia jungle, wrought with a lack organization and a bad search function.

 

Well, fantastic. After installing all of the nVidia stuff, (I've got the nVidia GeForce 8800 GT) Steam games suddenly work. Synthesia still mucks up with a window on top of it (excluding the taskbar/Start Button menu), and now I'm using Google Chrome because Firefox seems to have a small chance of randomly freezing everything.

 

Well, I re-installed Windows a while ago, and it went well. Then this started happening, again. So here's a shameless bump.
I'm fairly sure it has something to do with DirectX, but I'm no expert on that visual hardware to software relationship.
As for the GFX drivers, Nvidia just released a big update that I happily accepted, but that was after this started happening, again. Nothing changed. And I always keep Java and Flash updated, and Synthesia is the latest version.
Here's some generic information from HWiNFO:
Motherboard: ECS MCP61PM-GM
Chipset: nVidia nForce 6100-405/430

 

What do these have in common? I feel like that'll weed out the issue.
Windows Pictureviewer, Synthesia, Realm of the Mad God (Steam executable version, haven't tested browser), and TheBest404PageEver.com's SWF loop in the middle of the page in Google Chrome? Almost anything overlapping these windows will cause the issue described in my first post.

 

(I'm installing SP2, now.)
The red /!\ marks I have are under "Other Devices" listed as "Multimedia Volume Controller," "PCI Simple Communications Controller," and "WD SES Device USB Device" (I've got hidden devices shown, too.)
I've already updated my SMBUS drivers and Chipset drivers. I have no clue what the issue is. The graphics card is around 4 years old, now. Do they have a short life expectancy, perhaps?

 

I'm not on my home computer at the moment, but I've got a few new updates. I tried running Saints Row: The Third on the computer, and it ran perfectly for the first few minutes. Once I got to the actual game, however, the screen was plagued with blue horizontal lines, and it became completely unresponsive. I rebooted, and the BIOS was coated in an evenly spaced cascade of little white dots.
Windows booted once, I went to run some tests on the drivers, I accidentally overlapped two bad windows, the display froze, and I rebooted. Same white dots, and the text in the BIOS was now jumbled a bit. It took me to the little loading bar in Windows, and then the screen simply went into power saving mode.
I decided to boot a portable copy of Ubuntu I had lying around, and that at least started up, but the blue lines still persisted. I figured it was probably best to let my graphics card take a rest, so I shut the computer off and cleaned/reseated the card. Same junk still happens.
I'll try and test it with a spare card when I get home.

 

(Didn't realize I was logged into another household account, please disregard this post.)

 

Now that I've fixed the login issue, I'll relay my current woe. I have no other graphics cards to test. What should I do?

 

I'm sure you guys will love another bump.
I'm back on my main machine, completely forgot that I had a VGA. I'm running on that, all the distortion is fixed.
But the overlapping issue is still present. Sorry for not uploading these sooner, totally slipped my mind. Here's your Everest report and your startup programs.

 

I've got one around this generic "Multimedia Video Controller"
Under properties, I have
-General tab-
Device Type: Other devices
Manufacturer: Unknown
Location: PCI bus 4, device 0, function 0
Device status: The drivers for this device are not installed. (Code 28)
To reinstall the drivers for this device, click Reinstall Driver.

-Driver tab-
Driver Provider: Unknown
Driver Date: Not available
Driver Version Not available
Driver Signature: Not digitally signed

-Details tab
-
I'm not quoting everything under the "Device Decription" dropdown menu. There's quite a bit.

-Resources tab-
Resource settings:
This device isn't using any resources because it has a problem.

 

Also, my VGA is updated. Still no luck.

 

Hardware IDs:

PCI\VEN_14F1&DEV_8880&SUBSYS_D4391461&REV_0F
PCI\VEN_14F1&DEV_8880&SUBSYS_D4391461
PCI\VEN_14F1&DEV_8880&CC_040000
PCI\VEN_14F1&DEV_8880&CC_0400

And how would I go about the second part of your post?

 

Last night, I went through Advanced Systemcare 5 and had it check my registry. It found a massive amount of DirectX issues and attempted to clean them up. For about an hour, everything ran fine. Synthesia and Windows Explorer could overlap in harmony, and even Minecraft could rest pleasantly under the start menu without everything freezing. After a reboot, however, everything went back to being busted. I've tried reinstalling DirectX 9 and 10, no luck.