so im having some problems regarding my pc, whenever i ALT TAB from a game or quit the game for a few seconds the main display shows this wierd white grain with a view coloured dots, then when i tab back in its gone.
also whenever i keep my pc on and it goes in to sleep mode when i wake my pc up my left monitor dispplays these wierd green lines flickering randomly in my screen and the display becomes very slow and laggy
also when the game is closed my background turns to a pure black screen see picture for reference
i have no idea how to fix this pls help. ps sorry for bad english