I've tried the Windows Update Agent (WUA) 3.0 & update 927891, it did not solve the problem. WUA has been installed previously and did not need to install it again. When install update 927891, my SP version newer than the update and do not need to install this update. Though this problem has been there so many years, still there is no way out.

For a while I just stop it by turning off the windows update & automatic updates (Manual) and BITS (Manual). Although it can stop for a while.
Or is there another way, Is there anyone know another way to solve this problem, thanks..