Error 0x80244022

Value: -2145107934 | 0x80244022 | 2149859362

What does it mean ?

WU_E_PT_HTTP_STATUS_SERVICE_UNAVAIL  
HTTP 503 - the service is temporarily overloaded.
Value: 16418 | 0x4022 | 0b0100000000100010

Where does it come from ?

FACILITY_WINDOWSUPDATE  
Windows update
Value: 36 | 0x024 | 0b00100100

Other Errors for FACILITY_WINDOWSUPDATE