链接Sql 2005 express版本报错~~求解

我昨天在虚拟机上安装了一个Sql 2005 express版本，装的时候也没报错，装完后打开管理工具，登录数据库系统的时候报错了
错误信息如下：

TITLE: Connect to Server
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Cannot connect to \..

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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: 25 - Connection string is not valid) (Microsoft SQL Server, Error: 87)

For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=87&LinkId=20476

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BUTTONS:

OK
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各位来看看这是什么错误啊？
虚拟机装的是windows 2003 server R2的系统

用SSMS本地登陆后运行sp_helpserver，把结果帖上来看看

怎么本地登录？现在登录都登不上