مشکل در نصب sql server 2008? کمک

دوستان سلام

در هنگام نصب sql server 2008 R2 در قسمت server configuration ارور میده و دیگه نمیشه نصب کرد.

[Error Message]
The credentials you provided for the SQL Server Agent service are invalid. To continue, provide a valid account and password for the SQL Server Agent service.

[Details]
Microsoft.SqlServer.Configuration.Agent.InputValid ationException: The credentials you provided for the SQL Server Agent service are invalid. To continue, provide a valid account and password for the SQL Server Agent service.
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[Error Message]
The specified credentials that were provided for the SQL Server service are not valid. To continue, provide a valid account and password for the SQL Server service.

[Details]
Microsoft.SqlServer.Configuration.SqlEngine.Valida tionException: The specified credentials that were provided for the SQL Server service are not valid. To continue, provide a valid account and password for the SQL Server service.
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[Error Message]
The credentials you provided for the Analysis Services service are invalid. To continue, provide a valid account and password for the Analysis Services service

[Details]
System.ApplicationException: The credentials you provided for the Analysis Services service are invalid. To continue, provide a valid account and password for the Analysis Services service
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