Windows 7 choppy & lagging animation

[riezs]

Hi all..good day..

I'm kind a new here..need u guys help to my unresolved problem..well I'm facing win 7 start up problem which is choppy & lagging animation but finally enter the windows as usual..but when click file explorer or menu maximise and minimise effect is also choppy & lagging..it not happen often but its quite annoying..I use to pull out the ram and change it to other channel..(4 slot were occupied) restart then its back to normal..but later then in some other time its re-occur again,whatbmight seem the problem /cause of it? thanks for your help in advance

 

My system:

HP 8200 

i5 3.30ghz 2nd gen

16 gb DDR 3..1600mhz 

Asus GTX 750 OC 2gb 

WD RE 2TB Sata HDD Primary

WD RE 1TB Saya HDD Secondary