Once a patch is out on steam, you're bound to install it, period. Digitally obtained copies or retail copies not installed by disk (that happens when you redeem the code, associate it with your account and download the game, instead of using the disk to install it) will download the entire game prepatched, while retail copies will only install a part of the game usually, and download the rest later.
If there's no option in-game to try disable the said enhancements, at least to see if they're the actual cause, your best bet would be to look into configuration files and see if there are any manual options.