The MD button (line) can be used to restore (initialize) all Device Configuration Block (DCB) parameters of the WM2000 to their factory defaults.
The M/L V4 flowchart shows how to do this (the DCB reset is at the very bottom of the flowchart). Alternatively, follow this infographic detailing the shortest path to the DCB reset:
Once the green status LED turns on, you are in the Wi-Fi Phase. If the autoconnect parameter is set to yes, the WM2000 will attempt to associate with an access point. To skip this, you need to press the MD button (pull the MD line LOW) as soon as the green status LED turns on and before the association occurs. If the association is happening too fast, turn the access point off or move out of its range.