Hi
um..I think the problem has been solved.
I want to try windows's system restore. But make a backup of the hard disk first.
So I turned off controller,Remove the hard disk(its transcend 60GB ssd,lol),With ghost64 on the hard disk to do a backup.
and When I have done all this, ready to boot into the system restore, it is normal to start up.
It looks like some settings are automatically updated because of a long power outage.
Anyway, now it can normally boot up. The next time to do so, I will be sure to do a good job of hard disk backup.
Thanks