So I've been reading through a lot of posts on here, and a lot of people seemed to have trouble with the cutscenes and videos not appearing. So far, I've had no trouble with those, but when it comes down to the actual gameplay, the image completely disappears save for this little box in the upper left hand corner. The rest of the controls are apparently still intact, as I can move my character around--and the audio still plays as well. I can see that the graphics are there in that tiny little box at the top, but the rest of the screen is completely obscured. Going into different resolutions doesn't bring the image back either. I downloaded the patch that came with the game when I bought it, but that didn't do anything either.

I'm running the game on Windows 7 with an Intel(R) Core(TM) i3-2310M with an Intel HD Graphics driver

Update #1
I've been told a similar bug happens in System Shock 2, and the way they fixed it in there was to go to the cam_ext.cfg file and find the line that says:

multisampletype 8

and add a semicolon so it says ;multisampletype 8

They said you can open cfg files with Notepad, but when I try to open it in notepad, the file doesn't even appear in the list of documents that can be opened in it. Does anyone know how to open cfg files in notepad, or any kind of legit software?

Update #2
Figured out how to get into the cam_ext.cfg file, but that specific line of text doesn't exist in the file, so I'm not sure if the problem is even in there or not.

yeah, intel "gpu" (insert dr. Evil image here).

http://www.gog.com/forum/system_shock_2/major_graphics_bug_black_screen_with_small_square/post2

In the Open dialog switch to All Files (*.*) vs Text Documents.

you need to open the cam_ext.cfg file in the Thief folder, not the one in the docs folder, anyway, the line is there, ctrl+f to find it if you are using notepad.