Verify the paths including this one:
C:\Windows\System32\XCOPY.exe
Also using the ~1 notation is sketchy (IMO), spell it out and use double-quotes to delimit it, ie:
" F:\Program Files\Microsoft SQL Server\MSSQL\backup\ETKPS\*.*"
Concidently, I am fairly sure it is your reference using the ~1 sntax that is the problem.
CEWII