Here are directions on how to connect your Samsung Galaxy SII to a Windows XP computer.
1. Go to Menu>Settings>Wireless and Network
2. Next go to USB Utilities
3. Next Select Connect Storage to PC
4. Follow the instructions on the Screen
5. After inserting the USB Cable into the phone select Connect USB Storage
6. Press Ok on the screen
7. The Android symbol will turn Orange and you are connected. When you have transferred your files and you are ready to quit, at the bottom of the screen with the Orange Android Icon select Disconnect USB Storage and you’re done!