How to root the Toshiba Thrive AT100 running Android 3.2.1 Honeycomb

Have you been looking for an easy way to root your Toshiba Thrive AT100? If your tablet is running on Android 3.2.1 Honeycomb, we have just the thing that you are looking for. It doesn’t matter if you’ve got the U.S. or Canadian version because one rooting tool can do the trick.
Gaining root access on the Toshiba Thrive is possible through Fastboot but for those who upgraded to the Android 3.2.1 Honeycomb OTA update, it’s useless. Toshiba removed Fastboot from the U.S. and Canadian versions of the Toshiba Thrive, making it impossible to gain root access.
Fastboot was removed because DRM for renting of Google Videos was added, leaving other users to find an alternative way to root the device. Toshiba, however, heard users complaining and offered a rollback. Ironically, the move became useless because there is now a new and easier way to gain root access on the Toshiba Thrive running on Android 3.2.1 Honeycomb.
Through the combined efforts of developers dalepl and TurnYourBackAndRun, a script was created to easily root any U.S. or Canadian version of the Toshiba Thrive, as long as it was running Android 3.2.1 Honeycomb. It works by putting Fastboot back in the Recovery menu, flashing a root-enabled boot image and ClockWorkMod Recovery, installing the su and busybox binaries, install Superuser.apk, and make symlinks needed for busybox. Just flash this script and you are good to go.
If you want to root your device using this method, see the requirements and instructions below.

Requirements

• A Toshiba Thrive AT100 with Android 3.2.1 Honeycomb
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
• • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.
• Make sure that your battery has at least 50% charge to avoid interruption due to power loss.
• Make sure USB Debugging is enabled on your Toshiba Thrive.
• Download the Universal easy root tool (DaleNet-Thrive_Universal_Easy_Flash_Tool-v1.6.zip, md5sum: 349a4686c13bca66b82635b654e2d5fc) to your computer.

Disclaimer

• The instructions in this guide are intended for use of Toshiba Thrive, model number AT100. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Instructions

1. Extract the Universal easy root tool zip file to any folder on your computer, It is recommended that you place it on your desktop where you can easily see it.
2. Go to the folder where you extracted the files and open the folder named usb adb drivers.
3. Right-click on USB_ADB_Drivers_Eng_Multi_x86_x64.EXE and from the popup menu, select Run as Administrator.  This will install the USB ADB drivers to your computer.  If your computer complains about installing unsigned software, install it anyway.
4. Connect your device to the computer via USB.
5. Run the Universal_Easy_Flash_Tool.bat file by double-clicking on it.  A command prompt window will open and will provide you with informational screens.
6. You will be asked to choose whether you want to root, unroot, or flash custom recovery to your tablet.  Select option 1 (“Root your device”) by typing “1″ at the prompt and pressing Enter.
7. When asked, locate your ROM’s build number or version from the list and follow the instructions on the screen.  The rooting process will begin.
8. Check that rooting was successful:
   1. On your tablet, tap on APPS on the main screen and select Superuser.  You will see version information about the Superuser app.
   2. Close dialog.  You will see log information.
   3. Tap on the wrench icon at the upper-right corner of the log info screen.  You will see the properties screen.
   4. Scroll down and find “Su binary [version number]“.  Tap on this line.  The updater screen opens and displays the message “Current version already installed.  No action required.”
   5. At the bottom of the screen, tap on the Update Anyway button.
   6. Start over from step 8.a if you encounter problems with updating.

Your Toshiba Thrive AT100 is now rooted, has Superuser 3.0.7, BusyBox 1.19.3, and ClockworkMod Recovery 5.5.0.4. You can now flash custom kernels or ROMs and scripts on it. Congratulations!

Source: http://www.androidauthority.com/toshiba-thrive-at100-android-3-2-1-honeycomb-root-clockworkmod-recovery-93523/