EDIT: The latest Unreal Engine versions now support VS 2015. The information below in this post is now outdated.
Now that Microsoft has released Visual Studio 2015, and they are encouraging people to use their latest version, I wanted to take a moment to remind everyone that Unreal Engine 4 does not currently support Visual Studio 2015. Yet. We are working on finalizing support for Visual Studio 2015, and it will be coming soon in a future release version. For now, please continue to use Visual Studio 2013 as we will not be able to provide support for Visual Studio 2015 until the Engine officially supports it.
If you need to download Visual Studio 2013, you can do so from this page. Click “Visual Studio 2013” on the left side of the page, and make sure Community is the selected option (or whichever version you are looking for). Choose your language and format from the options, and click Download. One quick note about the “Web (Online)” format option: The file that was downloaded for me here in a couple instances did not have an extension. Adding a .exe extension allows you to then run the installer.
We will make sure to let you know when Visual Studio 2015 is supported by the Engine.