SQL Server Setup & Upgrade forum

I’m having an issue installing the latest hotfix/update for SQL Server 2012 SP1. I am trying to install SP2, but when I tried through Windows Update, it would come up with an error code of 0x851A0020. I tried restarting the server, and re installing, same problem.
I tried disabling the SQL Agent and just making sure nothing is running before the update process, that didn’t help either. I do have SQL Toolbelt installed on top of SQL Server 2012 SP1, so I don’t know if this could be the problem preventing the update.
I haven’t tried uninstalling it, as it is a pain to set it up again.

I tried downloading the SQL Server 2012 Service Pack 2 package from Microsoft’s website for manual installation, and I tried installing it that way. I received the same error message during installation. Keep in mind that all the pre-update checks to make sure
SQL Server 2012 SP2 can be installed passed before I went onto the installation, and no users are active in the database during the installation.

The error details had the following:

Error installing SQL Server Database Engine Service Instance Features. The registry key System\CurrentControlSet\Services\MSSQLSERVER\Performance is missing. Error Code: 0x851A0020.

Doing a Google search doesn’t result in any answers. There seems to be no error code details available for this error.

I tried going ahead and recreating the Performance key in RegEdit, and that allowed me to pass the first error message, but now I get another error message:

File C:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\Binn\DllTmp64\sqlagentctr110.dll could not be copied to file path C:\Windows\system32\pref-MSSQL11.MSSQLSERVER-sqlagtctr.dll. Error code: 0x85500003

Once again no information can be found about this error on Google.

Any suggestions would be greatly appreciated.

Thank you,

Peter