Posted by Jayce Ooi as How to
If you have Samsung Kies installed, whenever you plug in USB cable between Samsung Galaxy S II and PC, Samsung Galaxy S2 will be detected as GT-I9100 in Computer. And Samsung Kies will be loaded. You can disable Samsung Kies from loaded automatically by turn off Auto-run ~ Run Samsung Kies automatically when device is connected at Samsung Kies Tools – Preferences. You can read / write your Samsung Galaxy S2 files in this MTP Application mode. However, certain operation like unzip file to SGS2 directly is not possible in this mode.
USB mass storage
How to enable USB mass storage on Samsung Galaxy S II?
Your SGS2 internal storage and SD card should be detected as Removable Disk in Computer. Unzip operation is working fine in this mode. But Samsung Kies does not. Therefore, remember to turn off USB debugging mode if want to sync with Samsung Kies.