If you install into program files as non-admin, and create a mirc.ini in program files (and OK the necessary prompts :D), mirc (even when run as non-admin) will create it's stuff into program files, even though Vista will store it in VirtualStore.
Some apps can't handle it because they hardcode to C:\Program Files\ and can't find the files in VirtualStore, but I know from experience that mIRC 6.21 (so I'd assume newer versions too) doesn't have any problem with the situation because it uses %ProgramFiles%, which Vista can detect and redirect to VirtualStore when needed. I'm not sure how complete-package-scripts handle it, but I don't recall issues with NoNameScript 4.03, YMMV.
