PHP exec() not executing swipl

I want to execute command to run SWI_Prolog. My command generated correctly, means that when I run it in command prompt I'll get the output but when running it through exec($com, $out, $ret) it wont work and the value of $ret is 1.
Generated command is:

swipl -1 -f D:\xampp\htdocs\virastar\files\script.pl -g main(
    'D:\\xampp\\htdocs\\virastar\\files\\prepared_4329.vis',
    'D:\\xampp\\htdocs\\virastar\\files\\4329_final.vis') -t halt

Once again I have to say when I run it directly in command prompt it word correctly.
Any help will highly appreciated.