1. Enable USB-dev mode: Settings -> Applications-> Development -> USB debugging
2. Connect the USB cable
3. On the phone choose "Install PC Companion"
4. Install USB Driver (updated 2010-05-31)
Install the PC Companion (version 2.00.115). Let PC Companion update (and download a new version, my was 2.00.134).
This is how it will look in Device Manager when the Sony Ericsson ADB Interface driver is installed
5. Reboot the computer
6 . Optional: Uninstall PC Companion (in my opinion the program does not add any real value). The USB drivers will not be uninstalled.
7. Check that is works
C:\Documents and Settings\Lennart>adb devices
List of devices attached
Set up a Run Configuration on one of your Android projects and choose "Manual" target: