Grimrock

I bought it via GoG.

The x86 installer won't let me install; it claims that I already have a newer version on my system.

http://i.minus.com/ibg1dhbNDrt3QC.PNG I've installed this game on two different computers, multiple times each. This error is all that I've ever been able to get. I know Grimrock is supposed to be old school, but unintelligible errors that prevent one from ever playing is a little too authentically...