Cannot open Device explorer while connected

Hi, every time I click the SGH D980 icon on on PC Studio, I received this dialog box saying, "Cannot opne Device explorer in PC Studio mode. Please change to Mass Storage mode in the device's USB setting menu and try again."

I dont know why it is very difficult to manage this Samsung New PC Studio, I am using Windows XP and IE8.

All I want to do is to follow what the DEMO instructed in managing the several task like, transfering files from PC <=> Mobile. The icon MyComputer works, but for the SGH D980 it is not.