How to dual boot your NOOKcolor

This tutorial is no longer being updated. I’ve closed the comments section. I sold my NOOKcolor and no longer keep up on development. If you are interested in a fully functional, inexpensive Android tablet you may want to consider the Google Nexus 7. If you require additional help, please check out the NOOKcolor XDA forums here.
Since this tutorial was written Google renamed their app store. Instances of “Google Market” or “Android Market” now refer to “Play Store”. If that isn’t confusing enough, when you drag the “Play Store” icon to the desktop to create a shortcut the text on the icon changes to “Market”. So just know that these terms are interchangeable.

There are a lot of different options out there for how to add functionality to your NOOKcolor. I’ve already covered rooting [here]. I decided to look at another avenue. I decided to look at dual booting from your microSD card. The greatest benefit that this process provides is that there is absolutely no risk to your NOOK. It works or it doesn’t but your stock NOOK software and the eMMC memory it resides on is left untouched. That means if you have an issue, you just turn off your NOOKcolor, remove the microSD card and stroll on into Barnes & Noble and they are none the wiser. Your warranty is intact.

Before we begin I’m going to recommend a piece of hardware and I’d like you to strongly consider going with exactly what I recommend. There are a lot of people smarter than me behind this recommendation, and it has to do with the speed of a particular part of the microSD card. Usually speed can be determined by looking at the class of the microSD card. You can find cards out there all the way up to class 10. But I would like you to avoid that particular mindset and buy a slower class card by a particular manufacturer.

Hardware recommended: SanDisk Class 4 microSD card. 8GB [here] or 16GB [here] or 32GB [here]

That being said, if you have a microSD card laying around (that’s at least 1GB) and want to try it. Do it. The results may be fine. They may at least make you realize you love the end result and want to upgrade your card or it may make you realize that Stock or Rooted Stock is the way for you. There are no wrong answers. It’s all personal preference.

For the sake of information sharing, I just happened to have a SanDisk 8GB Class 4 MicroSD card available.

Let’s get started.

– – – – –

Step 1: Download Size-Agnostic SD Card Image

Download verygreen’s Size-agnostic SD card image [here].

You should now have a file named generic-sdcard-v1.3.img.gz.


– – – – –

Step 2: Extract Size-Agnostic SD Card Image

You can open the .gz file in any supported compression software. I use 7-zip. It’s free and it gets the job done. If you need a copy of 7-zip, you can download it [here].

I double clicked on generic-sdcard-v1.3.img.gz to open it in 7-Zip.


Click Extract


I chose to extract it to a folder I’d create on my desktop called NOOK but you can save it wherever you want.

Click OK

You should now have a file named generic-sdcard.img.

– – – – –

Step 3: Download Win32 Disk Imager

Download Win32 Disk Imager from [here].

You should now have a file named

– – – – –

Step 4: Extract Win32 Disk Imager

I double clicked on to open it in 7-Zip.


Click Extract


I extracted it to my NOOK folder in a subdirectory called w32imager but you can save it wherever you want.

Click OK

You should now have a folder with 7 files in it wherever you chose to extract it.

– – – – –

Step 5: Launch Win 32 Disk Imager & Write Size-Agnostic image to the microSD card

Some folks have issues with this step. More often than not the problem seems to be with the app and not the person using it. 90% of the issues seem to be resolved by going to an earlier version of Win 32 Disk Imager. If you find you are having problems with this step, give and older version of Win 32 Disk Imager a try. There are links on their website.

Go to wherever you extracted Win 32 Disk Imager in Step 4 and double-click on Win32DiskImager.exe.

Note: If you’re running Windows 7 UAC may popup and ask if you if you want to allow the program to make changes to the computer. In this instance, it’s okay to press Yes. You must press Yes or you’ll be unable to continue.


In Win 32 Disk Imager, click the Blue Folder.

Select generic-sdcard.img.

Click Save.

Make sure the device listed in the device drop down is your microSD card’s drive letter. When I plug my microSD card into my PC it becomes drive G. So you can see [G] in the device dropdown above. Your drive letter may vary. Please be sure you chose the right drive letter. I would hate for you to erase some priceless family memories because you wiped out your cameras SD card instead of your NOOK’s microSD card.

When you’re sure you’ve got the right device letter selected, Click Write.

You may see the following message:


Click Yes.

You’ll see the writing process begin.


When writing completes press Exit.

– – – – –

Step 6: Check your work

Double click on My Computer. (Or browse to your microSD card any which way you know how)

Your microSD card should now be named boot and have 4 files on it: MLO, uboot.bin, uImage and uRamdisk.

Note: In the past I’ve been asked if it’s important that the icons look alike, no it is not. My .bin file is a traffic cone because of another piece of software I have installed. Don’t let the fact that our icons look different worry you.


If you don’t have those files stop now. Do not continue. Repeat Step 5.

– – – – –

Step 7: Safely Remove the microSD card and then put it back in again

In Windows 7, you can do what I’ve detailed below. Highlight your microSD card named boot by clicking once on it. Then click Eject along your tool bar. Alternatively you can also right click on the microSD card drive and choose Eject. If you absolutely cannot find a way to eject the media from your computer you can also just restart your computer. You’ll achieve the same effect.


After you’ve ejected it and pulled it out of your computer. Count to 5 and put the microSD card back into your computer. I don’t know why. It’s in the directions I followed writing this, so I’m passing it along.

Side note: Some folks have noticed that the microSD card is now showing as only 115 MB. That’s alright. It’s temporary. When you install CM7 in step 9, the size will be restored to you. The install process will recreate the partitions CM7 needs.

– – – – –

Step 8: Download the latest CM7 Nightly Stable Release

Originally, when I wrote this tutorial, the latest CM7 nightly had functionality that was far superior the the latest stable release. This has changed and the latest Stable is highly functional and most importantly stable. And stable is what most folks who would want a tutorial like this would be interested in.

Download the latest CM7 Stable Release from [here]. As of this edit, the latest stable release is 7.1.0 (


When the download is complete move it to the root of your microSD card. If you are using a newer nightly your file name will vary a little bit but should look pretty close to the following image. However, note that the will be released with the CM7 Stable Release file you downloaded most recently. If you were doing this today, the would be replaced by


Now safely eject the microSD card. Check Step 7 again if you’ve forgotten how to do that.

– – – – –

Step 9: Install CM7

Despite the fact that we’re now going to be putting this microSD card into your NOOKcolor, you should know that nothing at all is being done to your NOOKcolor itself. All of the stuff you see come up on the screen next is happening to the microSD card itself. I could get technical but that’s not why you’re here. If you want technical, head on over to XDA. They are awesome there and the stuff they do is mind blowing.

Your NOOKcolor should be completely off before we begin.

Put the microSD card into your NOOKcolor.

Turn it on. You’ll see a loading screen and then you’ll see a lot of mumbo-jumbo. Yes, that’s a technical term. It’ll look similar to this:


When this process is done the NOOKcolor will shutdown.

Congratulations CM7 is now installed on your microSD card.

– – – – –

Step 10: Boot CM7 and setup Wi-Fi

Hold the power button until your NOOKcolor begins to boot.

You’ll see a little green CyanogenMod icon.


Wait a moment longer and you’ll see the cyan android on his skateboard.


When the loading completes you’ll be at the CM7 desktop. palmtop? I don’t know. Whatever it’s called, you’re there. =)

You’ll need to setup Wi-Fi before we begin the next step.

Press Menu

Press Settings
Press Wireless & networks
Press Wi-Fi settings

If your home wireless access point is broadcasting its name you’ll see it displayed under Wi-Fi networks.


Press the name of your wireless network or manually “Add Wi-Fi network”. If you’re on a secured network, you’ll need to provide your network’s password.

Once you provide the password you’ll notice a status will pop up under Wi-Fi. It’ll show connecting, Obtaining IP address and finally “Connected to (your network’s name)”.


Now that you’re connected you can shut down your NOOK. Hold the power button on the side. A menu will popup. Choose Power off. When prompted to power off choose OK.

Take the microSD card out of the NOOKcolor in preparation for the next couple of steps.

– – – – –

Step 11: Download Play Market & Google Apps

Download Google Apps from [here].

You need to scroll all the way down to the bottom. There is a subsection called Google Apps. You need the Google Apps for CM7. As of this writing the most current version was: 20110828.


You should now have a file that has a similar name to

– – – – –

Step 12: Prepare the microSD card to install Google Apps

Take your microSD card and put it back into your computer.

Your computer should recognize it as the same letter as before. It’ll still have the boot name. If you open the drive you’ll notice that the is gone. It has been installed and deleted. This is perfectly fine. Now we have the available space to move Google Apps there for installation.

Take the Google Apps ZIP you downloaded in the last step and place it in the root of the microSD card. It’ll look like this.


Now safely eject the microSD card. Check Step 7 again if you’ve forgotten how to do that.

– – – – –

Step 13: Install Google Apps

Your NOOKcolor should be off right now. If it’s not, shut it down before we continue.

Put the microSD card back into your NOOKcolor.

Hold down the N button on your NOOKcolor and hold the power button until it starts to boot. Once you see the NOOK’s screen come on continue holding the N button but let go of the power button. This will bring up your alternate boot menu. It’ll look like this.


You will need to change the Boot Mode at the very least. Here are the desired settings.


You change these by moving the cyan bar over the option you want to change by pressing, Volume + and Volume –, and then pressing the N button on your NOOKcolor. They also call this button the Home button.

Once the settings are the same as above you can select that third option of Boot Now. Press Home to confirm.

You’re going to see more mumbo-jumbo. It’ll look like this:


When it finishes the install, the NOOKcolor will shutdown.

– – – – –

Step 14: Configure Google Apps & Device Setup

When you boot up, you’ll be greeted by a familiar site IF you’ve ever owned an Android phone. It’s the setup process.

You’ll be welcomed to your NOOKcolor. Press the Android to begin.


Next you’ll be asked to create a Google account or login to an existing. You’ll have to chose the option that is right for you but I already have one, so I chose Sign In. I’d strongly discourage you from choosing Skip.


After choosing to sign in, I am asked for my credentials. I logged in with my Gmail account.


After my credentials are accepted another message box pops up that offers to install some Google apps en masse. It’s up to you if you chose OK or Cancel. I chose OK.


If you pressed OK you’ll see the following menu. Many of them don’t install as they should. Facebook is one of them. You can click to enlarge this image.


If you check an application that doesn’t work you’ll see this:


If you checked an application that does work you may or may not see a Android Market (now Play Store) screen. You’ll want to click the FREE button. And then I think you have to press it again to approve.


When you get through installing all the applications you chose from that menu, you’ll be in the home stretch. It’s time to finish up the initial setup.

You’ll be prompted to Use Google location. Read the description and make whatever decision feels comfortable to you. I left both boxes checked.


Backup and restore is another decision that’s up to you. I appreciate this feature. I kept both boxes checked.


Now you just get a notice that your Google Account is linked. Click Finish Setup.


Finally, you’ll be prompted for your time information. I just had to choose Eastern Daylight Time and the rest was correct.


– – – – –

Step 15: Poke around. Pat yourself on the back. Consider making a donation.

That’s it. You’ve done it. You’ve taken your NOOKcolor and added CM7 to it via the microSD card. You can open the Market(now “Play Store”) and install the free version of Angry Birds or perhaps the Kindle app. Maybe the NOOK app for when you don’t want to switch over to your eReader partition to read. You could install Facebook or Google+, Goodreads or Cut The Rope. It’s really up to you now to really make it yours.

Speaking of making it yours. There are a couple more things to note. You’ll notice there is a phone icon on your default menu. That’s because CM7, like Android, was originally written for phones. Any icon on your desktop can be removed by pressing and holding your finger to the icon. At the top of the screen you’ll see a garbage bin. This doesn’t uninstall the app. It just deletes its shortcut. It’s still in your app drawer. You can also add apps to your desktop the same way. Just press and hold the icon until the app drawer disappears and then put it on your desktop wherever you want.

Oh, guess I should point out how you navigate around CM7.


1. This button brings up the App Drawer. This shows all the applications that are installed on your NOOKcolor.
2. This is the menu button. It’ll bring up different settings in different applications. It’s like right-clicking your mouse.
3. This is the back button. It goes back to the last screen or page you were on.
4. This is the search button. If you’re like me, you’ll probably never use it. It searches. Imagine that. =)
5. This is the quick notification bar button. If you press it, it will pop up the notification bar. You’ll find out what that does as you use your tablet.
6. These are just indicators to show you which screen you’re on. By default your NOOKcolor has 5 desktops. You can use those screens to organize your apps, etc. Press this to go to the next screen, or press the icon on the same icon on the other side to go back to a previous screen. Alternatively you can just flick the screen left or right with your finger to scroll through the different screens.

So I guess that’s it. You made it this far. You have a CM7 powered NOOKcolor. Well done.

If this helped you, or if I’ve helped you in the past, I’d like to ask you to consider making a donation. If you’re not interested, no biggie. Forget I mentioned it. =)


verygreen for the Size-agnostic SD card image and instructions – [here]
The entire CyanogenMod team – [here]