(Might as well chime in here)

Moving the location of the data for mIRC to the Application Data folder will also make it impossible to use on flash disks. I too prefer the data to be left with the program. It also makes it much, much easier to have multiple copies, and easier to back everything up for mIRC when it's all contained in one folder. No need to search for where everything was stored then. To me, it seems cheap that Windows doesn't let a program write to the folder it's located in unless you are have elevated user privileges.