how to disable "print on both side"

I installed adobe reader 10.1.2, and found when I printing ,the default setting always print on both side, how to disable that by registry file or other ways?

My printer has both side print function but we did not set up this as default.

why I hope disable this by registry file is I have over 500 users, I hope i can do it by .bat file.

any idea?

Thanks,

Ant