The PBT_APMRESUMECRITICAL message is sent as a notification that the system has resumed operation after a critical suspension caused by a failing battery. A driver receives this message through the WM_POWERBROADCAST message.
dwData = (DWORD) lParam;
No return value.
Because a critical suspension occurs without prior notification, resources and data previously available to a driver may not be present when the driver receives this message. The driver should attempt to restore its state to the best of its ability. While in a critical suspension, the system maintains the state of the DRAM and local hard disks, but may not maintain net connections. A driver may have to take action with respect to files that were open on the network prior to the critical suspension.
This message is not sent to applications.