New Android SDK puts adb executable file on \platform-tools directory instead of tool. Run Windows command line tool (cmd) and go to D:\android-sdk-windows\tool.Connect the phone to your pc/notebook usb port.In order to use ADB, you have to enable USB Debugging option in phone settings ( Settings->Applications->Development)
Extract SDK package into anywhere on your drive (Ex: D:\android-sdk-windows).Download Android SDK package (Ex: android-sdk_r06-windows.zip).Download and install Java SDK (Ex: jdk-6u20-windows-i586.ex e).This tool is usefull for communicating with Android phone such as install application, copy files from/to device and perform some linux shell commands. ADB is bundled with Android SDK package that can be downloaded from Android SDK download page. Android Debug Bridge (adb) is a tool that lets you manage the state of an emulator instance or Android phone.