Error 0x80070643: Fatal error during installation - WSUS v3.0 SP1

I have been trying to upgrade from WSUS v3.0 to WSUS v3.0 SP1 but the upgrading process is ending with an error saying "Windows Server Update Services could not be upgraded". I have gone through WSUSSetup.log and i see "Error 0x80070643: Fatal error during installation" in each line. I want to know if there is anything i can do to get rid of this errors and upgrade to WSUS v3.0 SP1 successfully.

Just go through below article and try out the solution that has been mentioned there for fixing that error. I have gone through the article and it says Error 0x80070643: Fatal error during installation occurs when user who is running WSUS Setup does not have System Administrator permissions in SQL Server.