Some people install mIRC incorrectly. I will try to explain it simply.
In Windows Vista, 7, 10... a program cannot make any changes to any files stored under C:\Program Files\ or C:\Program Files (x86)\
If you selected "Portable Install" at some point when installing mIRC, what will happen is that the file mirc.ini gets installed under C:\Program Files (x86)\mIRC\mirc.ini
If this happens, only the Windows Administrator can make changes to mirc.ini, and so mIRC cannot make normal changes to your settings. They become lost.
All of the above also applies to other files like servers.ini, users.ini vars.ini scripts.ini popups.ini, et al.
There are a couple solutions.
1) Create a folder at C:\Portable\mIRC\ and move everything from C:\Program Files (x86)\mIRC\ into it. Update your Start Menu shortcuts. You're good to go.
2.a) Go to C:\Program Files (x86)\mIRC\ and delete all of the .ini files within that folder. Alternately, you can backup all these files into a different location, but ultimately the .ini files (and specifically mirc.ini) CANNOT be in that folder.
2.b) After mirc.ini has been removed from C:\Program Files (x86)\mIRC\ then mIRC will write mirc.ini and your other settings files to the correct App Data folder under your User Directory. You can replace some of these settings files with those that you backed-up earlier.
The main point here is that only System Administrators and applications with Administrator Permission can make changes to files stored under C:\Program Files\, and it may be that you accidentally installed mIRC as "Portable" in this location. A "Portable Install" puts both mirc.exe and mirc.ini into the same folder so it can be toted around on a USB flash drive or cloud storage.
