How to secure aspx website

Hi every body …

I am a PHP web developer with a good experience security concept using ( PHP / apache )

I need learn of how to secure (aspx) website for example I want to learn how to

1- not to execute aspx file in image folder
in PHP / apache I use
RemoveHandler .php .phtml .php3
RemoveType .php .phtml .php3
php_flag engine off

2- Shell scanner … I download a shell scanner to check PHP shell … is there any tools to check aspx tools

3- I also want to add folder password such as .htaccess password

and I will be very thankfull for any idea or information could help me