How do I get the latest RACHEL USB version?

RACHEL can be installed on any device. Please visit our RACHEL page to see more info. We also "sell" units at no-profit for those who cannot complete the download in the RACHEL store. We're a small group and this is difficult to fulfil, please try yourself first.

This quick guide describes how to get and use a RACHEL server, the self-contained package to run on Windows computers (For the instructions for the Raspberry Pi version go to the RACHEL-Pi site). Updated version of this guide is finishing up here.


1 - Get a 32GB or 64GB USB flash drive ready.

You'll need a 32 or 64 GB USB Flash Drive (you may already have one, or many of them.., so in this case just skip this step..) to write to it the RACHEL-Stick package content. If you need to buy one try to get one with a fast read speed. There are lots of brands and prices, but a name brand is always strongly recommended. Also, usually the cheapest ones are very slow.

The RACHEL-USB content fits on 32 or 64 GB flash drives (depending on which version you're downloading), but of course you can copy it to a larger capacity one, on any other external storage type.


2 - Download the RACHEL package

BitTorrent Sync is now available for better reliability and consistency of download. Please consider familiarizing yourself with BitTorrent Sync. We do not support FTP downloads for all versions.

Version Language BitTorrent Sync Code
RACHEL 64GB USB English Coming Soon

You can skip to section 4 if using BitTorrent Sync as you will not need to unzip any files. This download may take days. It is only complete when the file ends in ".img" and not !SYNC. !SYNC is an incomplete download. Contact us if you need help.

The whole RACHEL content is alternatively packaged and compressed in just one file to download. The file is in the .zip format.

You are going to download it by FTP:

  • FTP connection: Host = , Username =, Password = anonymous, port = 21 (default).

A very good and free FTP client for Windows, Mac and Linux is FileZilla ( It has very important features (Keep-alive, auto reconnect) for downloading very large files like this.

Sample FTP login using FileZilla:

FileZilla connection


Once connected you'll see the files in the server available for FTP download. Go to the "rachel" folder and drag the file to a folder in your computer. Example using FileZilla:




The FTP download will start.

WARNING: These are very large files, which may take a long time to download.


Important: if you want to verify the integrity of the very large downloaded file, which is strongly recommended to make sure that it has arrived intact during the long download process, this is its md5 checksum: 7dc8665b78af274442cb2a1c0d49ba3f


To verify the MD5 checksum of the downloaded file you can use in Windows a free tool like WinMD5Free ( Sample screenshot:





3 - Expand and Install.


After downloading the large package file to your computer you have to unpack it, with a tool like 7-Zip or WinZip on Windows. 7-Zip is a great tool, open-source and free (

As an example, here are screenshots from 7-Zip on Windows selecting and unpacking the large zip file:


- Select the downloaded zip file:




- Pick a location for the RACHEL content. You could create a new directory or folder for it. You could also extract directly to the 32 GB USB drive plugged to the computer, though you may prefer to save to the computer hard drive to have as "master", and then make multiple copies from it to USB memory sticks as needed.




- 7-Zip will the unpack the zip archive

As it is a very large file the above step may take a very long time, even hours in some cases.


When the whole extraction of the zip file is completed, you will end up with the whole structure of the RACHEL package on your local computer.


4 - Make the RACHEL drive.


Plug a 32 GB USB flash drive (stick), or other external storage device with enough capacity, into a USB port in your computer. In Windows this will show up as a new drive letter (like E: or D: ) in Windows Explorer.

Using Windows Explorer, select and drag the new downloaded content, from the location where you extracted it to in the previous step, to the USB flash drive. This will make a copy of the all the RACHEL content on the USB memory stick, that you can use to take or ship anywhere. This copy operation may take a long time also, as there are lots of files to copy.


How to use the RACHEL Server

There are 2 main scenarios to use the RACHEL Server package you have now with you:

Before you begin with either scenario, please be aware RACHEL will not function with a VOIP service running on your computer (Skype, Vonage). Also RACHEL requires a modern web browser.

  • The simplest one is to use these USB stick/s in a personal computer, for one single person or student to go through its content.
  • Another scenario, perhaps the most valuable, is to to make this rich educational content available to a local network, like to a school classroom or community center, where multiple students from their computer or devices web browsers can access the content served by the RACHEL web server. This makes possible also to quickly repurpose an existing Windows computer in the location to be used as a RACHEL server.

Let's review in detail those scenarios below


a - Play the videos on a single PC.

In this scenario a person plugs the RACHEL USB drive to a personal computer and with Windows Explorer goes to the location of the just plugged drive, like D: in this example:




The above screenshot shows the directory structure of the RACHEL package.

To start the RACHEL server just double click on RACHEL-START.exe, which will open the mowes window in your desktop, as in here:




The server will also at this point automatically launch the default web browser in the PC, connecting to the now running web server in it, and launching in the browser the RACHEL content:




From there the student can navigate the different content libraries that are part of a RACHEL server.


b - Serve the content to a local network.

  • Plug the computer or laptop with the RACHEL server USB drive to a local network. This could be an existing school network or a simple ad-hoc network for a few computers that you have setup with a simple consumer wireless router and network cables in a classroom or community center.
    The wireless router will make available the content to wi-fi computers or tables and phones. This could be a very simple sample setup in a classroom scenario, in this case using a Windows laptop with the RACHEL server running:



    Back view:


  • Find out the IP address of the computer acting as the RACHEL server:

  • From a command window in the PC with the RACHEL server, use the ipconfig command:



  • Or if you have the Pi plugged to the router you can also connect with your browser to the router administration interface and see the assigned IP address to the computer where RACHEL is running on.


    Or you can just you a phone connected to the same wi-fi network created by the wireless router and use a mobile app to scan the local network and find out the connected computers . Just see the details of the device with the name of the computer you are running RACHEL. Make note of the IP address, in this example. (Using the Scany iPhone app for this screenshot on the right).

  • Note: later, if you use this solution in a semi-permanent setup, like on a dedicated school PC, you can assign in the router a static IP to the RACHEL server computer, so the IP will be always the same, and the users/students can just bookmark it in their browsers.

  • Now computers and devices connected to this network, wired or wirelessly (wi-fi), will be able to access and play the RACHEL content, just by entering the IP address of the RACHEL server in a browser URL field. in this example above. You can direct the students to enter this IP address in their browsers and they can start browsing and using the RACHEL content as needed:




Other possible scenarios:


Once you have have downloaded the RACHEL package, based on your on-the-ground needs, there are other ways the RACHEL content can be used. Here are just some examples:


  • If there is already a web server running in a given location, like a school with an internal network, you can copy the content of the "bin/www" folder in the RACHEL package to the documents root of the web server (like Apache, etc.) , which will make the RACHEL content available to any computer that connects to that web server.

  • You may have many donated laptops or PCs to send to remote communities. You can copy to each of them the whole content of RACHEL, so each computer user can access the RACHEL content on his/her machine, without the need to connect to a local network or use a external USB drive. You'll need about 30 GB of free disk space for this in the PC/laptop.

  • Are you familiar with the new RACHEL-Pi (RACHEL on a Raspberry Pi)?
    It provides a solution to run everything from a very small and cheap Raspberry Pi computer, a Plug and Play, ready to go solution to serve the RACHEL content. Read its details in the RACHEL-Pi site.

  • With the RACHEL USB card plugged to a computer, or with the RACHEL content copied to a computer hard drive, you don't need to start the server part of the package to access the content locally. The RACHEL content is organized in a way that you can just open its index page file (index.html file in the bin/www folder) in a browser, and navigate and play the content from there (Search won't work though, as it requires the full server for it)

    This will launch the PC default browser and automatically load the RACHEL main page.


  • What about if a location has Macs instead of Windows PCs? No problem. Though you cannot run this particular server from a Mac, you can use your Macs in 2 ways:


    • With a browser (like Safari or Chrome) access the RACHEL server running on another computer on the local network, just by entering the IP in the URL window, as done above with PC browsers.

    • Plug the RACHEL card into a USB port of the Mac, or copy the whole content of the RACHEL USB drive to the Mac HD. Then go with Finder to within the bin/www folder and double-click on the index.html file, as done above in the Windows example. This will launch the default Mac browser(like Safari) with the RACHEL main page, and then you can navigate the whole content from your Mac browser (Search won't work though, as it requires the full server for it).


What web browsers to use with RACHEL?

The "Khan Academy on a Stick" content included in RACHEL, with about 3,000 video lectures, uses HTML 5 video in mp4 format using H.264 video and AAC audio codecs. So to be able to play these videos you need to use a modern HTML 5 compatible browser version that also supports this video format.

You can see a list of supported browsers here The ones under the H.264 column and highlighted in Green are very likely to play fine the videos in this distribution.

For instance, as per today, Windows Internet Explorer 9+ and Chrome work great. Latest versions of Firefox (22+) for Mac and Windows work fine also. On the Mac, Safari, Chrome and Firefox 22+. On iOS devices (iPads, iPhones, iPod Touch) everything plays great with OS Safari: the videos can also be expanded full screen, rotated, etc. On Linux Chrome and Konqueror, on Android, well, it is a long story.., but please try yourself (there are at this time thousands of combinations of hardware-Android software versions out there. On some quality ones they play great for instance with Firefox for Android.)

Other pieces of content part of RACHEL include Flash animations, which will be played as well by the above browsers. Though those Flash animations won't play on iOS devices (iPads, iPhones) as Apple does not support Adobe Flash on iOS.

You can see a live online RACHEL instance at . Very useful to visualize the whole content that you'll have then available in your RACHEL distribution, to be used in locations with no Internet access. Also to try different devices and browsers.



Some notes: technical and other

  • A choice had to be made about the videos format. There is no single video format and video/audio encoding that can be played in all web browsers and operating systems out there (This table online shows which video formats are likely to be supported by a given browser). In this case H.264 video and ACC audio encoded videos in an mp4 container was chosen. This can be played on latest versions of modern browsers supporting HTML 5, as mentioned in more detail above.
  • The videos in this distribution are encoded in a relatively low bitrate, on purpose. This makes their file size fairly small, and makes possible as in this case to have a package with all this content that fits in a 32 GB memory card. RACHEL servers have been deployed in hundreds of remote locations around the world, and a reduced overall size has proven critical on the ground for downloading, installing on devices with reduced storage, cloning, etc.


Problems downloading or setting up a RACHEL server?

Please do not hesitate to contact us should you have problems to download, expand or use RACHEL. You can contact us as described in the About page and we'll be happy to respond.