Thanks guys, but autologon is the solution I use for the moment even before I started this tread.
I run some datacenters with hundred servers for living, so I was trained to keep computer security in mind and autologon = huge security hole. That's why I keep on searching more secure solution. I don't want to wake up one day only to find that somebody easily tap into my music server and removed my entire music collection.
Anyway I'll try to install MC16 to another computer and see if MC can accept uPNP query on Windows startup (not on Windows log-on). I'll let you know the result.