No permission to change SQL configuration!

It is surprise to me after upgrading SQL Server Express Edition from 2008 to 2008 R2.
When I follow the official guide about SQL upgrade procedure step by step, I get the bad result that it is no permission to change SQL configuration.

What? The local administrator has no permission to change anything on SQL environment!
It should be default right to do this. Why get this error? Whether I cannot do this on the specific environment about booting from VHD?

Althogh I try to reinstall or repair method to fix this problem, but it still fail. Until I find out the article by Google and try it again, the finial problem is resolved.

The full steps is as the following expression:
1.download SQL Server 2008 R2 Express Edition from Microsoft Web site
2.Extract this file to Drive C belong to boot from VHD
3.Execute command to rebuild system database for Windows Authentication Mode (known as rebuild master)

for example:

C:\sql2008r2source>setup /ACTION=REBUILDDATABASE /QUIET /INSTANCENAME=SQLEXPRESS /SQLSYSADMINACCOUNTS="your computer name"\ADMINISTRATOR

Microsoft (R) SQL Server 2008 R2 Setup 10.50.1600.01Copyright (c) Microsoft Corporation.  All rights reserved.

4.log on the local computer by administrator to realize whether has right to setting SQL configuration

BINGO! It is normal for me now.
I don't know what happen and why this problem is resolved because I am not SQL expert. I just know the previous issue disappear now.

Thank someone for me to post the good information on Internet. This is why I also post it on my Blogger for sharing knowledge.

By the way, I think it is very lucky because there is no any important data on SQL. If it is true, I don't know what happen after doing rebuild system database. Maybe I will lose the original permission or happen other issue!