After try and try and try, I finally concluded that running Windows on Mac Mini (Last 2009) no longer stable enough to be useful, and I have no choice but switch back to OSX.  This is sad consider that I have been using my MacMini as a main desktop machine since years ago.

The problem started about a month ago.  I rebooted my MacMini and found that the system hanged.  Rebooted after rebooted and I still couldn't get the Windows 7 partition running again.  So I had no choice but reformat the partition and install Windows 8 Consumer Preview.  Things were working fine until a reboot, and now the machine is once again hanged during the start up.

The only conclusion I can made is that something screwed up the system through Windows Update.  However, I can't pin point out which windows update screwed up the system, and I don't want to waste all my time to diagnose the problem.  I think it's just way better for me to simply leave it alone, and start using is just as a simple OSX machine instead.