Solved: GeForce 8800 GT thinks it's a GS?

I'm having a whole bunch of trouble with this..

First off, here's the report:

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows XP Home Edition, Service Pack 3, 32 bit
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 6000+, x86 Family 15 Model 67 Stepping 3
Processor Count: 2
RAM: 3327 Mb
Graphics Card: NVIDIA GeForce 8800 GS, 384 Mb
Hard Drives: C: Total - 305234 MB, Free - 182756 MB;
Motherboard: MSI, MS-7390
Antivirus: McAfee Anti-Virus and Anti-Spyware, Updated: Yes, On-Demand Scanner: Enabled

So. It says I have an NVIDIA GeForce 8800 GS, with 384 Mb.
However, what was bought was a GeForce 8800 GT. It even says GT on the GPU in the computer.

This is not my computer. (It is my girlfriend's dad's ha) He assembled it himself, and has been using it for games and such. However, a game that it should be able to run cannot, and I believe this is because dxdiag (and the computer) is reporting that it has less GPU memory than it actually does.
I know this is an odd problem, so after some searching and finding no related problems, I have come to one of two conclusions.

1. Her dad used to have a GS, and the computer (somehow) thinks that's what is still inside?

I've tried updating drivers, which of course just gives the latest v. of the GS.
I've also tried completely uninstalling the drivers, and updating drivers automatically, which gives same.
Also tried uninstalling the driver, then choosing the 8800 GT driver on the disc provided with the GPU. That is just unrecognised. 4-bit colour and lowest resolution possible.

2. This is some weird GS packaged in a GT body.

Say What??

Any ideas? Will find any information you need if there is any thoughts!
Never seen anything like this before ha.