How do I solve the SQL problem

The login is failing - so the most likely thing is that the ID and password combination you are using is not valid for teat SQL server instance.

Try this: Simple SQL Connection String Creation[^] and use PC1 to establish a connection to the DB via Windows. When that works, you can look at putting the string into your app.

BTW: I would strongly suggest using a hostname instead of an IP address - they tend to change when machines and / or routers are power cycled. It also means that if a computer dies, another can be given the same hostname and all apps continue to work.