Android/Eclipse: where to write command-lines like "emulator -wipe-data"?

to set the wipe option on Mac, with the Android SDK Manager running, click the start button to launch an AVD. A Launch Options window opens. There is a Wipe User Data checkbox about half way down.

Open command prompt & goto

android-sdk-windows\tools

Then for the following command:

emulator -avd -wipe-data

use something like:

emulator -avd myandroidavd -wipe-data