To vyflusnul google, stačí hledat ;)
start -> run -> regedit -> HKEY_CURRENT_USER -> Software -> Valve -> Half-Life ->Settings
Then you will see 'ScreenBPP' -> Right click -> Edit -> select 'decimal'
then just change it to 32 ;)
nebo taky tohle : Had the same prob. try this wright in launchoptions : -gl 32pps