I don't mean to flame but, honestly I think this is one of the dumbest threads I've read on the Vista/mIRC subject. Of course it has to be Vista compatible. For years everyone bitched and complained that Windows wasn't secure and now that it has made strides toward being a more secure OS, people are now bitching and complaining that it is too complicated. It really isn't complicated at all if everyone would stop complaining long enough to take a deep breath, calm down and actually think about it. mIRC was forced to comply with the changes and it did. The same things have been explained over and over and over until everyone is sick to death of explaining them. There are ways around these changes, which too have been explained over and over. One thing I think would make an improvement is if the installation path were followed in the Application Data dir.
If mIRC is installed to (or just run from) \Program Files\mIRC634
The AppData path would be \username\Application Data\mIRC\Program Files\mIRC634
If mIRC is installed to (or just run from) \Program Files\Chat\mIRC
The AppData path would be \username\Application Data\mIRC\Program Files\Chat\mIRC
Basically, whatever location mIRC is installed to or run from, the same path is followed in the AppData dir. This would allow for mIRC to be run from different locations, each location having its own settings folder rather than having to use shortcuts with command line switches.
~ Edit ~
RRX: This was a general reply and was not directed solely at you.