Helle
I am new to Web Development. So please help me to understand some basics. I want to send data from Web page to the serial port of my computer but I don't understand how to do. I have downloaded visual studio and wamp server in my computer how port of computer understand the request from Web page

 

https://support.microsoft.com/en-us/kb/823179
Edit. May be incorrect

Try this maybe?
https://sourceforge.net/projects/kle8309/