O erro 0x800702E4 significa ERROR_ELEVATION_REQUIRED.
C:\Users\André>err 0x800702E4
# as an HRESULT: Severity: FAILURE (1), FACILITY_WIN32 (0x7), Code 0x2e4
# for hex 0x2e4 / decimal 740
ERROR_ELEVATION_REQUIRED winerror.h
# The requested operation requires elevation.
# 1 matches found for "0x800702E4"
Você deve configurar sua tarefa para ser executada com os mais altos privilégios.