@mohsin20,problem is that no quad core runs cool enough to set up in a mini-itx cabinet that too in a space as restricted & with poor ventilation as yours.you can setup such a system but i seriously doubt that the system will be stable if you leave it on for long duration of time.also kaspersky is cpu intensive during scan & most people usually schedule scan during night when going to sleep.
the best renderer when it comes to picture quality is madvr & is supported by MPC-HC, Zoom Player, J.River Media Center, PotPlayer and KMPlayer.it is best because it acts just like a computer game & use graphics card processing power to render video.also since it is the best it is also the most difficult to configure & needs a decent graphics card costing ~4000 or above.if you are not comfortable with experimenting with settings,driver installations etc my suggestion is continue with evr.
forum.doom9.org/showthread.php?t=146228
@cilus,gpu accn is used by video decoder to decode video & does not affect the picture quality which is solely dependent on renderer.
madvr is the only renderer which uses graphics card shaders to process & render image & hence superior than any other renderer or post processing filter.it can bring a GT440 to its knees on a 30/60fps 1080i video