Hi. To be able to use the USB tethering on your Galaxy Young, do the following:
1. Connect the Galaxy S5360 to your computer using its USB cable
2. Navigate to Settings > Wireless and Networks > Tethering > USB Tethering (make sure the green tick shows)
3. Then on your computer - Go to Start > right-click "Computer" and select Properties
4. Click on Device Manager on the top left of the Window
5. Look for and right-click "BCM21553-Thunderbird" and select Update driver...
6. When it is done, then you should be able to share your internet connection with you desktop computer.