Flashing an SD Card with Raspberry Pi Imager
Getting an operating system onto the SD card is the one physical-media step every setup starts from — and it's easier than it sounds.
You'll need: a microSD card, a way to plug it into your regular computer (many laptops have a built-in slot; otherwise a cheap USB SD adapter works), and a downloaded copy of the free Raspberry Pi Imager tool from Raspberry Pi's official site.
Raspberry Pi Imager handles the entire process in three steps, right from its own interface:
- Choose Device — select your exact Pi model, so the tool prepares an image built for your hardware.
- Choose OS — for this course, pick "Raspberry Pi OS (64-bit)" (or the Lite version, which skips the desktop environment entirely, if you know you'll only ever connect headless over SSH).
- Choose Storage — select your SD card from the list. Double-check this is actually the SD card, not your computer's own main drive, since the next step erases everything on it.
Before writing, the Imager offers an "Edit Settings" (gear icon) option — take it. This lets you pre-configure a hostname, enable SSH, and set your Wi-Fi network and password right now, so the Pi connects to your network and accepts a remote login the very first time it boots, with zero manual setup on the device itself. This single step is what makes the fully headless setup in the next lesson possible.