You HAVE to log on to windows with a user account, because the option to start on startup is actually start on log in. So, for each restart you have to log in to the server. There are ways of making services out of executables, so you can run it on startup, but I don't know if that would be successful as MC probably depend somewhat on the user account that MC is started in.
For the XP days you also had something called Powertoys, which allowed a XP client to automatically log on with a user. If you can use a similar application for your OS, this might be the simples way to deal with this problem. I would google ways of logging the user on automatically if I were you and had to have this function. Remember that security will be worse though. For most home users however, this has little impact.
