All those that I have encountered have found that adding
this DLL (direct download link) to their mIRC directory solves that problem. It seems to be a problem on AMD processors, and perhaps nVidia related too.
Please note, do
not replace the iphlpapi.dll with your Windows system default. Just place it in your mIRC directory, and see if that solves the situation.
You are, of course, welcome
Regards,
