Connection Problem on Windows 10

I have installed SQL Server Express 2012 on my Windows 10 test computer and copied a database to it. I have been unable to connect to the db. I added a rule to the firewall that opened port 1433 to all traffic. I am using the following code to test the connection. It works fine when I point to the original server but fails when pointing to the Win10 server, whether I use its IP address (192.168.1.140) or the address using NAT on my Linksys router.

Public Class Form1     Dim strConn As String = "Data Source="     Dim gMsg As String = ""     Private Sub btnTestConnection_Click(sender As System.Object, e As System.EventArgs) Handles btnTestConnection.Click         strConn += Trim(txtServer.Text) + ";Initial Catalog=HouseholdInventory;Persist Security Info=True;User ID="       &n ...