Can't connect to server on SQL Server Management Studio 2008

When I open the Management Studio and try to connect using the [PCNAME]/SQLEXPRESS it shows this error:

"Cannot connect to [PCNAME]\SQLEXPRESS"

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ADDITIONAL INFORMATION:

Error Message:

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"

I've also tried "localhost", "local" and "." in the place for [PCNAME] but to no avail.

Make sure SQL Server (SQL Express) service is running.

in powershell prompt type:

Get-Service -Name 'MSSQL$SQLEXPRESS'

service "status" property should be reported as "Running"

If it is not, type (you need to be in elevated prompt, i.e. "Run as Administrator"):

Start-Service -Name 'MSSQL$SQLEXPRESS'

OR

click start > type cmd and type

sc query MSSQL$SQLEXPRESS

State should be reported as "Running"

If it is not, type (you need to be in elevated prompt, i.e. "Run as Administrator"):

sc start MSSQL$SQLEXPRESS

If you get an error that the service cannot be found: Open SQL server Configuration Manager and make sure you have SQL server express installed: