Blender is a little different than how other programs work. Omar is correct. You don’t have to uninstall the previous version when you install the new version. They can both exist on your computer. So, it just comes down to personal preference.
More advance blender users tend to keep multiple versions. When taking a course on CGCookie they may recommend what version they are using in their video. That’s a hint that you might want to use that version if you are a beginner so you can more easily follow along. BUT! If you are comfortable navigating the UI changes that Blender makes then there isn’t really a need to go back.
Install/Uninstall/Update/Don’t it’s all up to you!
