Problems trying to connect to AWS EC2 using Putty on Widows

When I tried to use PUTTY to connect to Linux form my computer, it showed this. Is there something wrong with my public key? I do not know what I should do next. I have tried launching instances a few times but when I came to the last problem, it will show this. Could you give me some suggestions about what I should do next? Thank you a lot!

Have you tried generating a different set of keys (*.pem) files in AWS and using that when trying to launch a new instance, instead of using the same keys?

Yes! I have tried and solved it , thank you a lot!