When you click download on the official page, you will often see multiple files. Use this guide to pick the right one:

: Use this for 64-bit Windows operating systems.

To , you should generally aim for the SQL Server 2008 R2 SP2 version, as it is the most stable and feature-rich release of that generation.

: "Express with Tools." This is a bundle that installs both the SQL engine and SSMS together. System Requirements