tearing my hair out to be honest at this stage.
I have an installation of SQL Server 2008 express on my laptop. I\'ve been trying to login to SQL Server Management
I know this one is pretty old but I had the same issue today and fixed it by myself. The issue was an IP setting in the Sql Server Configuration Manager See here
I had an IPv4 in the IP-Addess field and changing it to an IPv6 made it work.