The Raspberry Pi's operating system runs off a removable SD Card, making it easy to save your projects or re-flash a clean image. Find below instructions on how to install a new or clean OS image and available alternative OS.
There is a wide variety of different operating systems available for the Raspberry Pi. Downloading a new OS and easily imaging the sd card allows you to test many different options.
You can save your current projects in progress by imaging the sd card and saving it on your computer for future use.
SD CARD IMAGE (use the
df command to identify if "sdb" is your sd card)
In Linux or Mac, for example:
sudo dd bs=4M if=/dev/sdb of=raspbian.img
Write backup image back to an sd card to boot in the Pi:
sudo dd bs=4M if=raspbian.img of=/dev/sdb