通过Microsoft Visual Studio的数据库连接

我在通过Microsoft Visual Studio(C#.NET)创建数据库时遇到问题.当我要创建一个新数据库时，它会产生一个错误:

建立与sql服务器的连接时发生与网络相关或特定于实例的错误.未找到服务器或该服务器不可访问，请验证实例名称正确且已将sql服务器配置为允许远程连接(提供者:SQL网络接口，错误:指定服务器错误/实例错误26)

当我没有安装防病毒软件时，我没有遇到任何问题，但是安装后会造成严重破坏.现在，即使禁用了防病毒软件，它也会产生相同的错误.

请帮我解决这个问题

预先感谢.

I am having problems in creating a database through the Microsoft Visual Studio (C# .NET). When I am about to create a new database, it generates an error:

a network-related or instance specific error occured 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)

I do not face any problems when I have not installed an antivirus, but after installation, it causes a havoc.. Now even after disabling the antivirus, it generataes the same error.

Please help me out in this matter

Thanks in advance.