The easiest way to do this, is to put a copy of the mirc.ini file in the same directory as the mirc.exe
When the mirc.exe starts up it look for the mirc.ini file in the directory where the exe is located.
If mirc.exe finds mirc.ini in that directory, then it uses that.
Otherwise it looks in the appdata\roaming directory.
The purpose of this change, as I understand it, is to maintain compatibility with the multi-user environment that Windows uses.
Additionally, note that using the Upgrade option in the mIRC installer will maintain the same settings and directories that you previously had.
