SQL Server 2012 SP2 update failure
Figured out the problem last weekend. After trying to run a repair on my SQL Server 2012, it reported that the user Administrator doesn't have the proper privileges in order to proceed with the installation, so I had to do the following:

Provide Full Control through Group Policy Management Editor in Computer configurations -> Policies -> Windows Settings -> Security Settings -> Local Policies -> User Rights Assignment to:


Back Up files and directories
Debug programs
Manage auditing and security log


More on this error here:
SQL Server installation fails