I bought the game on Steam and whenever I try to play it, nothing happens, I appear as "Playing The Witcher 2: Assassins of Kings" like two seconds and then I go back to "Online". Any help?
1. Try verifying the game cache through steam
2. If that doesn't help, start steam or the game .exe file as administrator. You can find witcher 2 exe in: your-installation-path\The Witcher 2 Enhanced Edition\bin\witcher2.exe
3. Check your documents folder, is there a folder called "Witcher 2"? It should contain subfolders "Config", "Downloads" and "gamesaves".