SQL Server - Error while installing sqlexpress 2008

 sir,
    icannot connect to sqlserver 2008 . it shows the error

TITLE: Connect to Server
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Cannot connect to LOCALHOST\SQLEXPRESS.

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ADDITIONAL INFORMATION:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)

For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=-1&LinkId=20476

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 sir please tell me how to fix it. Also sqlserver service is not installed in my system please tell me what to do ?

Thanks&Regards
Nami

This error comes means your sql express services are not running so check it
All Programs >> Microsoft SQL Server 2008 >> Configuration Tools >> SQL Server Configuration Manager >> SQL Server Services, and check if SQL Server service status 

if not running than restart it , that will fixed your problem.

also see this link more elobrate the network issue
http://www.sqlmusings.com/2009/03/11/resolving-a-network-related-or-instance-specific-error-occurred-while-establishing-a-connection-to-sql-server/ 

Hi,

Please first check if there is a named instance of SQL Server called “SQLEXPRESS” running on the host server. The error message indicates that the specified server/instance is not valid. Please check if you specify the correct server/instance name.

I noticed that you specify “user instance = true” in the connection string. User instance is a feature of SQL Server Express and does not supported by other editions of SQL Server like Enterprise or Standard. If there is no SQL Server Express instance on your host server, you need to attach the database to the SQL Server instance and modify the connection string.

Please refer to the following link to attach databases: http://msdn.microsoft.com/en-us/library/ms190209.aspx

If it’s a default SQL Server instance, you can change the connection string to:

Data Source=.;Database=ASPNETDB;Integrated Security=True;

If it’s named instance, you can the connection string to:

Data Source=.\InstanceName;Database= ASPNETDB;Integrated Security=True;

For more information regarding the error and SQL Server user instance, please see:

http://blogs.msdn.com/b/sql_protocols/archive/2007/05/13/sql-network-interfaces-error-26-error-locating-server-instance-specified.aspx

http://msdn.microsoft.com/en-us/library/ms254504.aspx

 sir,
   i checked for the service but service is not get installed .

If there are services are not installed than how can you connect it, you need to first install the sql server express instance on that machine than only you will be able to connect.