How do I fix the error 'Named Pipes Provider, error 40 - Could not open a connection to' SQL Server'?

Solving this problem is very easy:

1. Go to control panel.
2. search for services.
3. Open Local services window from your search results
4. Restart your MSSQLSERVER service.

Screenshot of the steps:

And the simplest solution - check if your slash is back...

I spent about an hour trying to figure out what's wrong with SERVER/INSTANCENAME when everything is configured correctly, named pipes, user access rights... and suddenly it struck me, it's not a slash, it's a backslash (\).

The horror, the shame...

It's a three step process really after installing SQL Server:

1. Enable Named Pipes SQL Config Manager --> SQL Server Network Consif --> Protocols --> Named Pipes --> Right-click --> Restart

2. Restart the server SQL Config Manager --> SQL Server Services --> SQL Server (SQLEXPRESS) --> Right-click --> Restart

3. Use proper server and instance names (both are needed!) Typically this would be .\SQLEXPRESS, for example see the screenshot from QueryExpress connection dialog.

There you have it.