title: sql server 2008 enable sa account
body: <p>I logged into my PC with administrator account. When I try to enable the 'sa' account of SQL Server 2008, I get the following error:</p>
  
  <pre><code>TITLE: Microsoft SQL Server Management Studio
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  Alter failed for Login 'sa'.  (Microsoft.SqlServer.Smo)
  
  For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&amp;ProdVer=10.50.1600.1+((KJ_RTM).100402-1540+)&amp;EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&amp;EvtID=Alter+Login&amp;LinkId=20476
  
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  ADDITIONAL INFORMATION:
  
  An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
  
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  Cannot set a credential for principal 'sa'. (Microsoft SQL Server, Error: 15535)
  
  For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&amp;ProdVer=09.00.1399&amp;EvtSrc=MSSQLServer&amp;EvtID=15535&amp;LinkId=20476
  
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  BUTTONS:
  
  OK
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  </code></pre>