I didn't do anything. All I did was download the file and unzipped it. I didn't move or change anything.
No worries! I would try deleting the files and downloading it into a new location - the error you got means that the .exe is looking for the files but they aren't where they expect them to be. Sorry for he hassle, hope that helps!
Alternatively, you can try the Steam version, which should do all that automatically.