I received this reply from mIRC. This solves the problem.
Sorry for the late reply.
If you register mIRC under the administrator account, the registration will be stored in the administrators current user (HKCU) location in the Windows registry, so it won't work with anyone else who logs into the machine.
However, mIRC does check to see if a registration has been stored in the Local Machine (HKLM) location. You would need to copy over the "mIRC"
section from the HKCU registry location:
to the HKLM registry location:
(I have attached an example file that you need to fill in with your
Now when you run mIRC from any account, it should see the registration.
Does that resolve the issue for you?
mIRC Co. Ltd.