## Creating an Install Drive {#creating-an-installation-medium .clear-float}
You'll need a USB flash drive with at least 2 GB of free space and a program called Rufus.
Download Rufus
 {.float-left}
1. Open Rufus
2. Insert your USB drive and select it in the "Device" list
3. Select "ISO Image" next to "Create a bootable disk using..."
4. Click  {.inline} to choose the ISO that you downloaded previously.
5. We generate a checksum (or hash sum) for elementary OS images so you can verify your downloaded file. This ensures that you've received the full, complete download and that your install image is not corrupted in any way. Click the `#` button in the status bar and verify that the text next to "SHA256" matches the following hash:
```bash nohighlight
48fcf51244c77e18ff68a8456a2e92e2b49270b9b3a1c7a60a88a9d358272c1e
wzxhzdk:0
Should produce the output:
```bash nohighlight
48fcf51244c77e18ff68a8456a2e92e2b49270b9b3a1c7a60a88a9d358272c1e
wzxhzdk:1
## Creating an Install Drive {#creating-an-installation-medium .clear-float}
To create an elementary OS install drive on macOS you'll need a USB flash drive that is at least 2 GB in capacity and an app called "Etcher".
Download Etcher
1. Insert the spare USB drive, and select the ISO file you've just downloaded.
2. Open "Etcher" and select your downloaded elementary OS image file using the "Select image" button.
3. Etcher should automatically detect your USB drive, but check to see if it has selected the correct target.
4. Start the flashing process by clicking the "Flash!" button. It will take a moment to get started.
5. When complete it will be safe to remove the drive and attempt to boot to install elementary OS.
The following dialog may appear during the flashing process, it is safe to ignore.
## Booting from the Install Drive {#booting-from-the-installation-medium .clear-float}
In order to start the installation process, you must boot your computer from the install drive.
* Assuming that your computer is still on, start by inserting your install drive and restarting your computer.
* After you hear the chime, press and hold
Option. Then, select the appropriate boot drive. Note that it may be incorrectly identified as "Windows", but this is normal.
* Shortly after selecting the appropriate boot drive, you should be presented with the elementary OS splash screen. You may now follow the on-screen instructions which will guide you through the rest of the process.
#### Boot Errors
If your Mac doesn't recognize your elementary OS USB Install Drive in the boot menu, you may need to create an elementary OS Install DVD instead. To create one, insert a blank DVD, right click on the ISO file in Finder, and select "Burn elementaryos-0.4.1-stable.20170517.iso to Disc". When complete, attempt to boot again from the Install DVD.
## Verify your Download {#verify-your-download}
Verifying your download is an important, but optional step. We generate a checksum (or hash sum) for elementary OS images and we recommend that you verify that your download matches that checksum before trying to install. This ensures that you've received the full, complete download and that your install image is not corrupted in any way.
Running the following command in your terminal:
```bash nohighlight
sha256sum elementaryos-0.4.1-stable.20170517.iso
wzxhzdk:2
## Creating an Install Drive {#creating-an-installation-medium .clear-float}
You'll need a USB flash drive with at least 2 GB of free space and a program called UNetbootin.
Download UNetbootin
1. Open UNetbootin from the Dash. It will open a window like the one below:
2. Select "Diskimage"
2. Click "…" to select the ISO that you downloaded previously.
3. Unplug all USB memory devices apart from the one you want to use.
4. Click "OK" and wait for the process to finish.
## Booting from the Install Drive {#booting-from-the-installation-medium .clear-float}
In order to start the installation process, you must boot your computer from the install drive.
* Assuming that your computer is still on, start by inserting your install drive and restarting your computer.
* Most computers will briefly allow you to change the boot order for this boot only by pressing a special key — usually
F12, but sometimes
Esc or another function key. Refer to the screen or your computer's documentation to be sure.
* Press
F12 (or the appropriate key) and select the install drive—usually "USB-HDD" or something containing the word "USB", but the wording may vary. If you choose the incorrect drive, your computer will likely continue to boot as normal. Just restart your computer and pick a different drive in that menu.
* Shortly after selecting the appropriate boot drive, you should be presented with the elementary OS splash screen. You may now follow the on-screen instructions which will guide you through the rest of the process.