Runtime Error '3706' VBA/SQL Server Error

I'm getting a runtime error '3706' Provider Cannot be found It may be improperly installed,

Attempting to connect to update a SQL Server database from a VB app in excel, heres the code:

Sub Open_INSQL()

Dim SQLConn As ADODB.Connection
      Dim strConn As String

      ' Assign the connection string to a variable.

      strConn = "DRIVER={SQL Server};SERVER=EBHPRMML350;UID=sa;PWD=;DATABASE=Runtime;"

      ' Create the Connection object.
      Set SQLConn = New ADODB.Connection

      'Assign the connection string and provider, then open the connection.
      With SQLConn
        .ConnectionString = strConn
        .Provider = "MSSQL"
      ' Valid Enums for the ADO Prompt property are:
       'adPromptAlways = 1
        '.Properties("Prompt") = adPromptAlways
        SQLConn.Open strConn
      End With