[Solved]Internet Explorer prompt "Request for permission to use a key" every time

I have imported a digital key but when I apply it, internet explorer always prompt a message "Request for permission to use a key" which is very annoying.

I searched but the posts in microsoft forum didn't point me to the right direction. Finally I figured out that the reason of this problem is that when I imported this key, I selected "Enable strong private key protection..." as shown below, which is by default selected.

Now how to solve this problem becomes very simple: delete the key and re-import it with the "Enable strong private key protection" check box unchecked. 

If you find this blog is useful, please kindly click the ads on this page to help. Thank you very much.