Note SQL Server 2012 Service Pack 1 was also made available on Microsoft Update on November 27, 2012.
Mandatory SQL Server 2012 SP1 hotfix
After you install SQL Server 2012 SP1, you may experience an issue in which Windows Installer starts repeatedly. This issue is described in the following article in the Microsoft Knowledge Base. This article includes a link to a downloadable hotfix that resolves the issue:
Note It is mandatory that you install this hotfix after you install SQL Server 2012 SP1.
2793634 Windows Installer starts repeatedly after you install SQL Server 2012 SP1
For more information about this issue, visit the following MSDN website:
Microsoft distributes fixes in service packs. Service packs keep a product current. They include hotfixes and fixes to issues that are reported through the Microsoft SQL Server community. Service packs may also include issues that our support organization feels have to be addressed. The most common metrics that are applied for triage of those items are customer call volume and customer satisfaction scores. These updates and components are conveniently bundled for easy downloading.
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. You do not have to install a previous service pack before you install the latest service pack.
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Microsoft SQL Server 2012 Business Intelligence, Microsoft SQL Server 2012 Enterprise, Microsoft SQL Server 2012 Developer, Microsoft SQL Server 2012 Standard, Microsoft SQL Server 2012 Express, Microsoft SQL Server 2012 Web, Microsoft SQL Server 2012 Enterprise Core