Before you can use your Raspberry Pi you need to install an operating system on a SD card. The following step by step instruction will show how it is done.
1. Go to raspberrypi.org and Download the RASPBIAN JESSIE LITE image as a zip-file. Obviously you can find it in the Downloads section of the website. (You don’t need the PIXEL image)
3. Next you need to download the Win32diskimager. With this program you can install the unzipped operating system on the SD card that is already connected to your Computer.
The Win32diskimager will look like this after you started it.
4. Select the file you unzipped in step 2 by clicking on the folder icon and navigate to the location of the file.
5. Select the Device with the letter of the SD card. Be sure you are using the right letter!
6. Click Write and wait until it is done.
7. For the last step you need to add an empty file to the SD card named ssh. It is necessary that the file has no extension. You can achieve this by creating a .txt file and deleting the .txt extension after name it ssh.
You can find a short Tutorial about how to delete a file extension here.
It should look like this afterwards:
7. Now plug the SD card into the socket under the Raspberry Pi.
That’s it you successfully installed the operating system on the Raspberry Pi.