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This tutorial is no longer being updated.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]

141 thoughts on “How to dual boot your NOOKcolor”

  1. I made the mistake of downloading the zip files at work- our company has a firewall that will rip individual files out of the zip archive, but make it look like everything came across fine. I had some of the problems people reported above- stuck in startup loops, a reference to, files not fitting on the 115MB partition. After pounding my head on my desk for a bit, I got a clean copy of the files downloaded on a different computer, tried again, and everything worked fantastically. Thank you!

  2. @Hayley – Yeah, I guess I need to be clear now that CM9 is an option that you want to use the CM7 links. As for your Wi-Fi situation, I’d probably try shutting it down and powering it back up and see if that stables things out. I’ve heard folks mention that it has. You may also try rebooting your wireless router. Some routers don’t play well with Nook, or so I’ve been told. My Buffalo and Linksys routers seem to be fine though.

  3. Fix for Vinny…

    Before ejecting the microSD at the end of Step 8, rename the CM7 zip file to begin with “update-cm”, then proceed.

    While running on the Nook, the code seems to requires a .zip file beginning with “update-cm” on the microSD, and the name of the CM7 stable released in June 2012 does not fulfill that requirement.

    Thanks for this great post Dusty…just the ticket for my very first dual-boot!

  4. Hi,

    Can you write a tutorial on how to dual boot nook color with ics?

    I can’t find any clear and simple guide on the web to do that?

    How do you named the process of replacing and OS like NookCOLOR?

    If it’s root, can you help root my NookCOLOR?

    According to your experience with Android, what is the best or top android budget smartphone on the market right now?

    Best regards,


  5. Stan – I’ve been really busy lately and I don’t know when or if I’ll get around to writing that tutorial. Last I checked, and admittedly it’s been a bit, CM9 was still in the Alpha stages for the NOOK. As such, I knew the process and directions could change so I’ve avoided it. That said I may need to look into it. Check back from time to time. I may write that tutorial after all.

    To answer your question on replacing the NOOK software, you basically look for a tutorial that has you installing the Android software to the internal memory, or eMMC. Find that tutorial, and you’ll find out how to overwrite the NOOK OS.

    Finally, I have to believe that the best budget Android smartphone on the market right now is the Samsung Galaxy Nexus. It’s being given away for free by some companies with a 2-year contract. Can’t beat free when it comes to a budget and particularly when that budget device is a Nexus device.

  6. How long does it take to boot up after the install? it’s been sitting on the cyan android from step 10 for a few minutes now…

  7. I really don’t think I’ve every had it take any longer than 5 minutes or so. In fact, I’m thinking it may be closer to just a few minutes. At that point in the process, you may be fine to just reboot the device by holding down the power button until it powers off and see how it goes. Some microSD cards are more finicky than others.

  8. Still stuck on cyanogen screen. But I was wondering if I could just install CM7 and google apps at the same time. I noticed that when it was installing CM7, there was a part that checked for the google apps file and since I didn’t place it on the sd card yet, it skipped over that step. Just wondering If I can install both cynogen and google apps at the same time.

  9. Thank you so much, your directions were clear and concise. But a little confused about if I remove the 8gb micro card, would the tablet still work and can I place a bigger micro sd card and what do i need to do. I donating some funds. Sorry so little but I am unemployed.

  10. FYI if your trying to boot Cyanogen 7.2 for some reason i had to rename to

  11. Thanks @7f369fa48171e8c1f240255cfe358bc5:disqus – I experienced that myself trying to update. I just hadn’t had a chance to go through the rebuild to check it out.

  12. Yeah @fb0600101e795e351370c231ec8517bc:disqus , If you remove the microSD card it will boot into the NOOK software as normal. If you wanted to move to a larger card you could make a copy of your card with the w32Disk Imager software and then restore it to the larger card. You’d then need to use a software like EASEUS Partition Manager Home Edition (Free) to expand that last storage partition to use the rest of the microSD card. It sounds a little complicated but it’s really obvious when you’re in the software. You’ll see the unused space marked as unallocated. Click expand and just drag the storage partition to occupy the unallocated space.

  13. dusty, when i out the sd card in, it says: ” host does not support reading read only switch. assuming write-enabled”
    and now nothing is happening at all
    Please help!

  14. Hi,
    Running v1.4.1 on my Nook Color. Everything goes well until I put the sd card in the Nook. It boots into the normal operating system. SD card shows the following folders/files: B&N Downloads, LOST.DIR, My Files, MLO, u-boot.bin, ulmage, that one as per instructions), uRamdisk.
    Using SanDisk 16GB, and have tried two different ones with the same capacity.
    Any suggestions??

  15. Even tried an old Kingston 4GB and the same results. I guess it’s just not reading the .zip file, because it’s still there and not deleted.

  16. Thank you so much; I was given the ever handy Color Nook for my birthday but was unable to access books purchased through Amazon for my Kindle app on my phone. Now I have access to everything imaginable and your tutorial/walkthrough was just what I needed; the pictures really helped!

  17. Thanks SO MUCH for this! Worked like a charm, did have to add “update-” to cm7 zip file as commented below- thanks for all the help and time you put into this! This was such a great detailed step by step post and I especially loved the screen shots, this was my very first successful dual boot! I am having a problem with google play music, it force closes. You tube works just fine. (I’ve read and found usually if one is fc, they both are, mine isn’t the case and most I’ve found is for cm9, wondering what to do with CM7) Any ideas? Thanks so much!

  18. turning the nook into a tablet worked great… Is there a way to get rid of the phone stuff or did I load the wrong CM

  19. My wife loves her new nook(android) tablet.. Thanks for the great how to do… Is there a way to turn off or remove the phone stuff it will hang on certain things??? Or did I load the wrong CM file…Thanks again ….Gregg

  20. No, unfortunately this version of Android (Gingerbread) was written for phones. It wasn’t until Honeycomb that a tablet interface was written. Honeycomb was never released by Google until Ice Cream Sandwich was released. Folks worked on a CM9 (ICS) version for the NOOK but it never left Alpha (or maybe Beta) stages. Then Jelly Bean was released and development shifted to CM10. So we’re still at a point where only CM7 has made it to “Stable” release. You can go to the XDA-forums and grab alpha or beta builds but they aren’t fully functional.

    So I guess that was a really long answer for “no” you didn’t download the wrong CM file and “no” you can’t remove the phone stuff. It isn’t hurting anything, not even battery life.

  21. Thankx Dusty…I’ve been all over everywhere looking for the SD Card image to duel boot from. Seems like this has not only gone viral, but commercial also. Thanks again for the upload!

  22. Hey Dusty — I sucessfully dual booted my NC with your help. The instructions and pictures were so clear; my only regret is that I didn’t come across your blog sooner. I’m running CM 7.1 right now — how do I go about updating to 7.2? Would I have to wipe the SD card and start from scratch? And is it worth it? Thanks again.

  23. Dusty, just wanted to add my kudos on this post. Extremely well-written and documented and thus easy to follow. Lucky, because I’ve had to do this a number of times as i experimented and got used to the new interface (I’m not an Android phone user). The big thing for me was turning on the “USB Storage Mode” on the NOOK at the end. I just couldn’t figure out why it didn’t show up on my PC any more. It’s all good now! Thanks and looking forward to more from you in the future…

  24. HELP!!! At Step 10: Boot CM7 and setup Wi-Fi, I was only able to get to “Wait a moment longer and you’ll see the cyan android on his skateboard.” The cyan android never showed up. What the heck do I do now? What am I doing wrong???

  25. Really messed up now. I downloaded the previous version of Cyanogen and tried again, didn’t work. Went back to download the most current version and it looked like it was going to work but after the Cyanogen anfd before the little man, the regular Nook came up ????
    What the heck am I doing wrong? I’m using a 32 GB SanDisk.

  26. Great article but I am getting stuck on step 9. everything looks good on the SD card Sandisk 16GB class 4 . when i power on the nook it goes straight to the “read forever screen” and loads.
    but here is the catch. I bought the nook tablet 8GB on eBay but the seller did not un-register it through barns and noble so when I wiped it clean and tried to set it up I am unable to get through the set up proses because I cant register the nook at all. the nook is a brick right now.
    will even be possible to load to the SD card when the nook is in this state?
    Thanks for your help.

    -Matt S.

  27. Great article but I am getting stuck on step 9. everything looks good on the SD card Sandisk 16GB class 4 . when i power on the nook it goes straight to the “read forever screen” and loads.
    but here is the catch. I bought the nook tablet 8GB on eBay but the seller did not un-register it through barns and noble so when I wiped it clean and tried to set it up I am unable to get through the set up proses because I cant register the nook at all. the nook is a brick right now.
    will even be possible to load to the SD card when the nook is in this state?
    Thanks for your help.

    -Matt S.

  28. Thanks! Great tutorial, everything worked like charm. I had to side download GMail, though. For some reason, PlayStore thinks it is incompatible. Also, other important apps cannot be downloaded from PlayStore: Evernote, Dropbox, CoolReader. Luckily, the APKs can be found on the Web, and can be installed.

  29. Hi. I came across
    your site while searching ways to do this. I actually used someone else’s instructions,
    but it is basically the same. I happen to have a 1gig MicroSD card which I used
    to play around and see what happens. There are a couple things I noticed; 1. When
    the card is in my PC I have unallocated space (space that is being lost), 2. (More
    of my concern) I wasn’t able to install the Amazon App store app (I was
    informed by the nook error message I needed to install a MicroSD card) the same
    was true for installing the nook app (this is my wife’s nook & she isn’t
    going to want to dual boot or remove SD cards). If I have a larger MicroSD card
    would that eliminate this problem? Thanks in advance.

  30. After the cyanogen loading screen disappears (referring to step 10) a lit blank black screen appears and nothing else happens, I tried to rebooting it a couple of times with the same result can somebody lead some assistance, I have no idea what I am doing wrong, help!

  31. Hi, my screen is stuck on the “cyan android on his skateboard.” it just keeps going and going. When I look into my SD card I also don’t see the .android secure files, etc. Any help is greatly appreciated~ I am using a sandisk 2GB card.

  32. When I try to write the image to my SD card with Win32DiskImager I keep getting an error that says “Not enough space on disk”. So I tried to use WinImage and get an error there that says “The current image format is not supported by the disk drive”. Am I doing something wrong or is the card I have just one that is not going to work?

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