Amnesia Graphics Problem

[Saiayoko]

Actually, my copy of the game does the exact same thing. Now, before anyone asks me for files and drivers and such... Please be aware that I don't know what I'm doing and will need to be linked to some form of tutorial on how to get these attach files and how to install/uninstall/update/etc a driver. I've looked everywhere for a solution, and I'm sure that it's a driver problem, but alas, because I am unable to figure out said drivers, I was forced to play the game in this state of 'liquid floor' and 'unplayable' sections. As an added misfortune, the famed 'water part' was part of these numerous unplayable sections, but I somehow managed to get through it...

Anyway, any help would be appreciated.

ps - I did not buy from steam. I was given a hard copy of the game for my birthday. I have upgraded to the 1.2 version, and I have an ATI graphics card (I believe it's ATI X1200, but I don't know off the top of my head...).