Like many owners of a rooted Nook Tablet, I was the unwelcome recipient of an over-the-air (OTA) upgrade to version 1.4.1 of the Nook operating system. This removed the Android Market and effectively killed root access. Bummer.
Unfortunately, this update also made it such that a “factory restore” would give a clean install of 1.4.1 instead of 1.4.0. Drats!
The good news is that an enterprising soul over at the XDA Developers Forum figured out how to easily downgrade your Nook Tablet from 1.4.1 to 1.4.0, effectively restoring its rootability. (link)
To do this, you simply have to download a .zip file containing the full 1.4.0 installer, copy it to your Micro SD card, pop the card into your powered-down Nook Tablet, and then boot it up.
As it turns out, the boot process is designed to look for this particular file and re-install the system if it finds it — basically a troubleshooting failsafe which can be used to overcome an untimely update.
If your Nook Tablet boots without running the update, you’ll need to try a different Micro SD card. For the record, my fancy new 32GB card wouldn’t work, but the old 2GB card from my son’s HTC Freestyle worked just fine.
There’s no need to re-format the card. Simply put the .zip file at the root level, pop it in, and hope it works. If not, try a different card. That’s it.
The main gotcha (aside from owning an incompatible Micro SD card) is that you might need to scare up a Micro SD adapter to load the .zip file onto your card. That said, it might be possible to mount the Nook via USB and drag the file to the card.
If you run into any problems — say, for example, that the N button stops working (mine did) — you have two choices…
Either do a factory reset, which involves re-booting and aborting the boot process eight times in a row, or simply deregister your device. To do the latter, you can access your settings by going tapping the clock/battery icon instead of clicking the non-functional N button.
Now, re-register your Nook and quickly turn off the wifi to prevent updates. Bam. You’re now ready to re-establish root access. Just be sure that you also block OTA updates so this doesn’t happen again.
Note: This same process should also work if you bought a new Nook Tablet and it came with 1.4.1 pre-installed.