Remote connectivity issues with multiple versions of SQL Server

Install the system Win7 has been unable to install sqlserver2012, later installed sqlserver2005, the former period of time because of the need to use sqlserver2012, try to install again, unexpectedly installed successfully. However, the sqlserver2012 remote connection is always unsuccessful, and the host name \ Instance name can be successful. Many methods have been found on the internet, and none have succeeded. I'll list all these methods first.

1. Double-click TCP/IP on the right

Open the IP Address option, pull to the bottom there is a ipall, set a TCP port, such as 1433 or 1444, set the OK, and restart the SQL Server corresponding instance of the service (TCP/IP protocol is not enabled, to enable), such as.

2, when connecting, pay attention to the format, format: "IP address \sqlserver instance name (this is usually seen in the service), port (this port is the TCP port set up in the previous step)", such as

This normal situation is not a problem, of course, if the SA account to be enabled, this is not said, and my computer so connected, always prompt

Unable to connect to 127.0.0.1\sql2012.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or could not be accessed. 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 the specified server/instance) (Microsoft SQL Server, Error:-1)

Sometimes prompt for memory access or write

Then I did the following 2 operations

1. Open cmd, enter netsh winsock reset, reset the Winsock directory, and restart the computer

2. Change the "built-in account" from "Network Service" to "Local system" and restart the SQL Server corresponding instance service.

This will be OK, or as the connection method

Connection Successful!