Hi Lu Zou,
Sorry for the delay reply. The server
has sp2 installed. Version 12.0.6425.100. There is no error
in the event viewer or the log file when I try to browsing to the page. However, there's a consistence error in the event viewer happen throughout the day:
The description for Event ID 27745 from source Windows sharepoint Services 3 cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.
If the event originated on another computer, the display information had to be saved with the event.
The following information was included with the event:
#50071: Unable to connect to the database SharePoint_Config on ******. Check the database connection information and make sure that the database server is running.
the message resource is present but the message is not found in the string/message table.
Again, none of the sharepoint site is woking, but sharepoint central administration is.
The database is running fine.