I find the cause of error.....the Master was corrupted....What I did was..

1. Copy the backup of *Master

2. Run C:\Program Files\Microsoft SQL Server\80\Tools\Binn\rebuilm.exe then point to the *Master where it located.

that's...

Yes, I clicked start in Enterprise Manager. I also tried in SQL Server Service Manager (the one in the taskbar).

Actually Sir, I also tried that in SERVICES but it is...