There are multiple systems available for Raspberry Pi. Most of them are based on Linux. The official system is Raspbian, a Debian based system designed for Raspberry Pi. The latest disk image is available at https://www.raspberrypi.org/downloads/raspbian.
After download the disk image, it needs to be written into the SD card. Note, the SD card will be formatted and all data will be removed. Please back up your data before continue.
For Windows, Win32 Disk Imager can be downloaded at https://sourceforge.net/projects/win32diskimager.
Insert your SD card, run Win32 Disk Imager as administrator, select the disk image as the source file and your SD card as destination. Click on write, then wait for the writing to complete.
For MacOS, no additional software is required.
First, insert your SD card, open Disk utility. Choose your SD card from the left. The table on the right indicates the device number of “disk1” (or any other number). Record that number. Then unmount the disk (on the top row).
Second, open Terminal. Type in the following command:
- sudo dd if=<path of raspbian.img> of=/dev/disk<number>
Where the input raspbian.img is the location of your disk image (usually at ~/Downloads/<date>raspbian.img) and the output disk number is the one recorded on the previous step. Hit Enter, and type in your administrator password, then wait for the writing to complete.
Hint: You can type only the first few characters of the image file name, after its directory, and hit on tab to auto select. When you enter your password, unlike when you login to the system, nothing will be shown for security propose. During writing process, you can use control+T to see its progress.
The writing process takes about 30-40 minutes for the full version of system (about 4GB). Eject the SD card and it’s all done!