always Install latest samkey:
http://www.samkey.org/SamKEY1890.exe
Install driver if needed: www.samkey.org/SAMSUNG_USB.exe
PROCEDURE:
1. Power ON Phone
2. Go to SETTING and open OEM and DEBUG!
3 After that dial *0808# then select ACM+DM+ADB
4. Insert USB cable
5. Press READ codes
6. wait until finish done