Selenium installation is a 3 step process:

  1. Install Java JDK
  2. Install Eclipse IDE
  3. Install Selenium Webdriver Files

Download latest version of "Eclipse IDE for Java Developers" here. Be sure to choose correctly between Windows 32 Bit and 64 Bit versions.

You can download Selenium Webdriver for Java Client Driver here. You will find client drivers for other languages there, but only choose the one for Java or Python.