The latest update from steam to stop the Ad-Killer in CS has also broken the Hl1 games with Steambuster Rev. A temporary fix is available for this problem. If your copy of HalfLife or blueShift keeps quitting to the desktop when run through steambuster then download this file HL Games fix and extract it to your steamapps directory replacing the existing file. Right click the game from the steambuster menu and "Delete the game(without gcfs)". Now run it in steambuster and enjoy Hl1 games offline again. PLEASE NOTE: While steambuster works happily with outdated GCFS, steam will try to "fix" this file when you run it.