Changing a new mIRC installation to legacy behavior:
- Run mIRC
- Type: //write $qt($+($nofile($mircexe),mirc.ini)) $null
- Close mIRC
- Run mIRC
Another method rather than a blank mirc.ini (before or after installation) is to just copy your files from the appdata folder to your mIRC folder after installing. The blank mirc.ini is faster, of course. I'm just offering another option.
I agree with genius_at_work. For the most part, only advanced users will care about where their settings files are stored. And they should know how to handle that situation without needing any special option in the installer. I always just upgrade anyhow, so it doesn't affect me. Well, I don't really upgrade... I install it to a temporary folder, then copy the files that I really need into my mIRC folders (mirc.exe, mirc.chm, and servers.ini).