WinInet / IE11 on Windows 7 TLS 1.2 enabled not working on a website

Question

I have some software where I use Windows WinInet API and IE browser control.

However a Windows 7 user is reporting problems if though TLS options are checked... I had the user try open the website using IE11 and that fails as well. (Which makes sense since it uses the same underlying API as my software)

The site apparently loads correctly in Chome.

Screenshots below showing the error and configuration:

Now I looked up the RC4 cipher mention in the IE11 error and found this: https://support.microsoft.com/en-us/help/3151631/rc4-cipher-is-no-longer-supported-in-internet-explorer-11-or-microsoft

Which essentially states that IE11 now like Chrome and FireFox no longer supports this... But since the user reports Chrome working for the website (and my Windows 10 Edge can load the website as well then...)

This seems to leave two explanations:

• The webhost is using another unsupported cipher?
• There is some security software blocking IE/WinInet at the API level on the users computer (the user states this is not the case)

Answer 1

Do you have SSL 2.0 enabled?

SSL 2.0 and TLS 1.2 are not compatible with each other in Internet Explorer 9 and later versions.

More info: https://docs.microsoft.com/en-us/troubleshoot/browsers/cannot-display-https-site