Qualcomm drivers are kind of tricky to install, thats why there is a short manual for you

1. Download and unzip Qualcomm drivers to the root of your hard drive C:\
   http://www.mediafire.com/download/hzm6hv081m7mic6/Qualcomm.zip for 32 bit computer
   http://www.mediafire.com/download/pjgk7nt9oh8ottv/Qualcomm64.zip for 64 bit computer
2. Uninstall 'Samsung PC studio software' and 'Samsung KIES" from your computer if they are present because they occupy the ports
3. Take out memory card and SIM card and turn your phone on
4. Turn off Bluetooth if its on
5. Go to Menu > Settings > Phone settings > USB settings. Pick the option "Samsung PC Studio" and press "Save"
6. Go to dialer, type *#782872# you will see ''Qualcomm mode configured, pls reconnect cable' and press "Confirm"
7. Go to dialer, type *#7465625# . Lock status screen will pop up
8. Connect your phone to the computer with original Samsung USB cable
9. Check the phone if it asks for a mode, if so select 'PC-Studio mode' or 'KIES' mode
10. Your computer will pop-up with new hardware wizard. Note: this step has to happen 2 or 3 times!

       Don't let it search in 'Windows Update' , choose 'No, not this time' and click 'Next >'
       You will now get:

        Instead of "Qualcomm Proprietary USB Modem (PID 3197) it can be one of the following
        "Samsung HS-USB Diagnostics 9002"
        "Qualcomm Diagnostics Interface 3197"
        "Qualcomm HS-USB Diagnostics 9002"
        "Qualcomm Diagnostics Interface 6000"

        Now choose 'Install from a list or specific location (Advanced)'. Click 'Next >'.
        You will get the next screen:

        Choose the first option and only tick the 'Include this location in the search:'
        Then click 'browse' and go to driver location C:\Qualcomm or C:\Qualcomm64 from the step no.1
        You will see:

        Now you will see:

        Click 'Finish'.   YOU ARE NOT YET FINISHED!

        After you clicked 'Finish' Windows will AGAIN pop-up with 'New hardware found wizard'.
        Do the step no.10 exactly the same again.
        Then when you come to the above screen 2nd or 3rd time click 'Finish' again and you are done.
        The qualcomm drivers are now installed correctly.
        For some devices (with GPS built-in) you have to do this process 2 times more!
        Because you will also be installing GPS driver; NMEA Device.

        Please come back to the UnlockClient now