Hello, at first i want to thank you, that at least someone answered, ive been looking for such detection - i also needed to tweak my application, because of wine does not support some functionality. Secondly if someone would bother to update, fix or do something with it, it would be great. Now for the problem: Its regarding UpdateLayeredWindow() function and transparency of the window. The problem is, that wine cannot show the window that uses alpha channel to specify transparency level for its every pixel. Actually im not yet sure if wine supports transparency at all.. I found the problem accidentaly few minutes ago, when i decided to try my windows application on my friends computer, who use wine. In fact it worked pretty well(i bow before wine developers :) ), but my good bye screen, who uses this transparency functionality was totally screwed up. I saw only white blank window. And unfortunatelly i cannot develope the project on wine, so i really need to detect wine and just not use this functionality.