Issues installing SQL Server 2012 I am trying to install SQL Server 2012. During the install I get an error saying 


  Error installing SQL Server Database Engine Services Instance Features
  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: TCP
  Provider, error: 0 - No connection could be made because the target
  machine actively refused it.) Error code: 0x84BB0001


I have run the setup  and given my user login and password as the account and password credentials for the all SQL server services (I'm happy with this, just need the program up and running to extract some data from a .mdf file)

I have set the database engine configuration to Mixed Mode and specified my password for the system administrator account.

The database engine does not install and the program tells me to uninstall these components and re-install them. I have done that several times now (using different credentials etc) not sure what to do next. 

I have previously had SQL 2008 running on this machine so dont think there would be anything preventing me from getting SQL 2012 to work?

I also managed to install the express version which installs fine. But the .mdf file I need to use is larger than 10gb.
The error message is the generic "I can't reach the SQL instance you've specified."  There are no components to "uninstall/reinstall", mixed mode/Windows mode are simply configuration settings.  I generally recommend you run in mixed mode.

Two things to check:


If this is a SQL Express instance, you should make sure your connecting to [Computer Name]\SQLEXPRESS.  SQL Express installs as a named instance, so as such needs to be connected to as a named instance.
By default, SQL Server installs without TCP protocols enabled, which would prevent most connections.  Open your SQL Server Configuration Manager, browse to SQL Server Network Configuration, and then Protocols for SQLEXPRESS.  Select that and look for TCP/IP and make sure it's enabled.


As for your file being larger than 10 GB, you'll need to use Standard Edition or higher, nothing you can do to get around that.  You can have a separate instance running alongside the Express instance, but if you want you can simply uninstall your Express instance as you would any other Windows program.