XAMPP for live server: stop access to root folder

[veeco]

Hello Guys,
i'm setting up XAMPP for a live server, and i'm in the process of hardening the security.. at the moment i have specific question. I'm putting a backdoor script and i'm surprised that the script can access and upload file to the root C:\ folder

What security setting i need to set in order to disable a site (virtual host) to be able to browse (and upload) into root folder ?

Thanks

[mark.mcdonald]

in the process of hardening the security.. I'm putting a backdoor script

If you want to harden security. Don't make a backdoor.