This is because "exec" looks for a program named "copy" and tries to execute it.

But there is no "copy.exe", (you can probably use xcopy.exe instead!).

Copy is one of the shell commands  that the shell handles itself.



For running shell commands, you should run "cmd" with /C param, and pass your command  .

For example, you should pass "cmd /C copy  d:\\music\\someFile.txt d:\\downloads" as the parameter for the exec method