Started game play and only the top left part of the screen was visible. Very new to PC games so not sure what to do about it. If possible, please redirect me to where I can fix this. Thank you for the help

I believe they did fix this with a universal patch, that you can download, just go to your library, click on thief and under the installer there should be a universal patch, it will install to the game automatically so its fine if your not a computer nerd.