There should be a pinned topic about this.
Default mirc settings are now stored in a public folder.
20.For Vista compatibility, new installations of mIRC now save all settings in the User's "Application Data\mIRC" folder by default.
However, if the installer or mIRC find mirc.ini in the same folder as mirc.exe they will use the mirc.exe folder for all settings.
Users installing over an old version of mIRC should therefore see no change in behaviour.
The installer is now also aware of administrator and standard user accounts and installs mIRC accordingly.
So either put your backed up ini file in this folder, or put mirc.exe in a different folder than the original setup folder with your scripts and backed up mirc.ini.
