Error code 2147942593 (hex 0x800700C1) is the HRESULT encapsulation of Windows error code C1, or ERROR_BAD_EXE_FORMAT
.
(search for 0xC1 in http://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx)
In a task scheduler this often occurs in one of the following cases:
The path points to a file that isn't an EXE program. If you literally entered the path to a DLL, this could be the cause.
The path includes spaces and isn't quoted. See Why "schtasks" does not run my job?