Try adding "-noborder" to your launch options. (Right click on the game in your steam library > Properties > Set launch options...) see https://developer.valv

Try adding "-noborder" to your launch options. (Right click on the game in your steam library > Properties > Set launch options...) see https://developer.valvesoftware.com/wiki/Command_Line_Options https://developer.valvesoftware.com/wiki/Command_Line_Option... for more options (I recommend "-novid -window -noborder -high -threads <number of threads that your processor supports>")