Batch file not working, command work fine if I run manual

Well, I was exploring the new function. Run a Script

1 -  Paser aria2c.exe in c:\windows\system32

2 - Test it, open cmd in everywhere, for example "c:\", I write aria2c.exe and the command run fine. 

3 - Make a simple script, aria2c.exe and the second line put a pause. 

The result is 

"aria2c.exe" no se reconoce como un comando interno o externo,
programa o archivo por lotes ejecutable.

If I run cmd from admin, manual work fine too, why doesn´t work from the script?

Thankyou!!