Thanks for your bug report. The reason for this is that Windows XP and 7 are no longer being updated by Microsoft. This means that all of their APIs, including those related to WinINet, which mIRC uses for $urlget(), are not receiving updates to handle new technologies. In the case of WinINet, it is trying to connect to an SSL server that is not allowing old/insecure ciphers. There is little an application can do to get around this with older versions of Windows, other than implementing features without using Windows APIs.
