After sufferred from upgrade SP1 of MOSS, I finally figure it out. Below are the steps:
1) First article should be followed here.
How to install WSS and MOSS SP1
2) If something goes wrong, you can use the command line before to see the details from the log file.
(Upgrade.log)
stsadm -o upgrade -forceupgrade - inplace
3) In our case, I did the following things.
a) Make sure the "Distributed Transaction Coordinator" service is started.
b) Make sure the remote connection configuration is "tcp/ip and named pipes".
c) Make sure the "sa" user of SQL Server is enabled in database.
Hope something can help you here.