I found that you can remove that background exe by removing below registry key.
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run]
PowerDVD12Agent
However, if you do use PowerDVD to sync media into your portable device, removing that registry key would cause the auto-syncing to be mal-function. You have to start PowerDVD to do the content sync.