A handy list of the direct links you need to download SQL Server Express. You can also download just SQL Server Management Studio 2014.
DOWNLOAD SQL SERVER 2014 EXPRESS
SQL Server 2014 Express with Tools. This download includes SQL Management Studio.
Here’s just SQL Server 2014 Management Studio
SQL Server 2014 Express with Advanced Services
DOWNLOAD SQL SERVER 2012 EXPRESS
SQL Server 2012 Express with Tools. This download includes SQL Management Studio.
Here’s just SQL Server 2012 Management Studio
DOWNLOAD SQL SERVER 2008 EXPRESS R2 SP2
SQL Server 2008 Express with Tools. This download includes SQL Management Studio.
Here’s just SQL Server 2008 Management Studio