‘php.exe’ is not recognized as an internal or external command, operable program or batch file

A:\xampp\php\php.exe

The PATH environment variable must contain paths only, not file names.

Make that

A:\xampp\php

it is very easy to do
You need to also add php.exe
Adding this path:
windows key + pause
click on Advance system settings
click Environment Variable
System variables part -> Path -> Edit and the add
C:\wamp\bin\php\php5.3.8;
close you cmd prompt if its open
It's Done!

I think you need to change it to A:\xampp\php\ and just leave it there, then it will search the directory for the file, also: have you tried calling just php instead of php.exe and check that the directory is correct.