Error 0x802451FF

Value: -2145103361 | 0x802451FF | 2149863935

What does it mean ?

WU_E_SIH_UNEXPECTED  
There was a failure for reasons not covered by another WU_E_SIH_* error code.
Value: 20991 | 0x51FF | 0b0101000111111111

Where does it come from ?

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

StackOverflow

Other Errors for FACILITY_WINDOWSUPDATE