To Download SQL Server 2012 Express:

Please refer Link:

https://www.microsoft.com/en-my/download/details.aspx?id=29062


Click Download.


Choose x64 if your Server PC is 64bit or choose x86 if your Server PC is 32bit > Click Next.


To Install SQL Server 2012 Express.

Step 1 - Click 'NEW SQL Server Stand-alone installation or add features to an existing installation'


Step 2 - Click Next.


Step 3 - Tick 'Perform a new Installation of SQL Server 2012' > Click Next.


Step 4 - Tick both option > Click Next


Step 5 - Click Next


Step 6 - Change Named Instance to QNEBSS > Click Next


Step 7 - Click Browse


Step 8 - Insert 'system' > Click OK.


Step 9 - Click Mixed Mode > Insert Password 'QnE123!@#'


Step 10 - Click Next


Step 11 - Start Installation


Thanks.


To know How to upgrade existing SQL Server 2008 R2 express to SQL Server 2012 Express