In our environment, HTTP server is having the self-signed certificate which is not installed in client machine. We are using "HttpSendRequestA" function to send HTTPS request from client machine to HTTP server. So we got the below security warning pop up during user authentication in client machine. We proceed with user authentication by pressing “yes” in below pop up window. The same function "HttpSendRequestA" is sending the request to server when the client machine is coming out of sleep/hibernate, or Laptop having WIFI connection reconnected to the server after 1 or 2 hour. In this scenario,, we dint get the below security warning.
I have few question for the above situations.

  1. Is there any chance for man in middle attack happen here?
  2. Does the untrusted certificate stored in my machine temporally when we accept the below pop-up windows?
  3. How to get the below pop up window when client network is changed?
  4. How to get the below pop up window every time when the user is sending http request to HTTP server?
  5. Do we have any settings in IE to get the below pop up window?

Appreciate for your help.
Security warning:
This page requires a secure connection which includes server authentication.

The certificate issuer for this site is untrusted or unknown. Do you wish to proceed?