problem with copy paste and some unwanted sounds

HI , 

i have some problems with  my computer (win 7 ) , after some times that i work with my windows copy paste goes wrong and also when i click mouse in the file explorer or in the google chrome ... my windows sounds ding and i can not change sound scheme until i restart my win or log off log on , i have tried sfc /scan and malicious software removal tool but they don't address the problem ,can you help me ? (i think it is due to  a virus  but my bitdefender 2013 couldn't find and kill it).

THANKS IN ADVANCE.