sql server 2008 enable sa account

Question

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:

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&ProdVer=10.50.1600.1+((KJ_RTM).100402-1540+)&EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&EvtID=Alter+Login&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&ProdVer=09.00.1399&EvtSrc=MSSQLServer&EvtID=15535&LinkId=20476

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BUTTONS:

OK
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Answer 1

Have you tried Microsoft KB956177 before?

To resolve this issue, make sure that you select the Map To Credential check box on the General tab of the Login Properties - sa dialog box before you change the "sa" login properties and then click OK to close the dialog box.