http://bugs.winehq.org/show_bug.cgi?id=3803
------- Additional Comments From blueflameruler@gmail.com 2005-12-12 10:47 ------- This is becuase you are running hl2.exe directly. To use this exe in such a way options need to be passed to the exe from Steam.exe. It cannot be run on it's own accord. You need to run Steam.exe first then run HL2 from steams menu's. This should fix your problem. Allthough, I'm not sure if and application calls to run an .exe is it run though wine or directly. If it is run directly one could only assume that it will be handled by your window manager as an "Unknown file", unless maybe you have configured Gnome or KDE etc. to run .exe's with wine.
All the best, --:::Hotwir3s:::--