Monthly Archives: March 2015

Enabling multiple users on Lenovo A10-70 tablet

One of the main features of Android since 4.2 Jelly Bean is the ability to have multiple user profiles so that, for example, you can share the same tablet between your family members and keep your toddler’s prodding fingers away from your precious email. This tablet shipped with Android 4.4 (KitKat), so I fully expected to be able to use this functionality. Unfortunately, for an unknown reason, Lenovo have disabled this. After contacting them, they claimed it was disabled because of stability issues, which I think is a poor excuse seeing as plenty of other tablets have it enabled. They also claimed that an Android 5 (Lollipop) update would be coming at some point, and that it will include multi-user support. We will see…

In the meantime, I have had to find a way to enable it myself. This is a 2 stage process:

  1. Root the tablet
  2. Change a setting to enable multi-user support

 First, root the tablet

I did not want to stray too far from the stock setup, I had no intention of installing a different ROM or anything else, so guides online to do with changing the bootloader were overkill for me.

There are various methods around to root android devices. There are a few toolkits around that will do this, but it seems that the most effective ones are also the most shady, in that they don’t publish their source code. You can’t know for certain therefore that all it is doing is rooting the device, and not sending information somewhere, or installing something that could spy on you. This is a risk you have to decide whether you are willing to take. The only one that worked for me was KingoRoot, which went through a rather scary sequence of downloading files and repeatedly rebooting the tablet. It did work however, so I have to give it that.

Step 2 – enable multi-user

If it was enabled properly, there would be a section of the settings menu in which to manage the multiple users. The method here will not enable this menu, but will allow you to set up your multiple users as a one-off task. This has proven fine, as long as you are not going to want to continually add and remove users.

Connect to your tablet

First, you need to get your tablet connected to your computer so that you can use some of the Android developer tools to modify files on it.

  • Download the USB driver from Google, or use Lenovo’s own driver which I had success with (local copy here).
  • Extract the zip file
  • Open the file google_winusb.inf and under both the [Google.NTx86]  and [Google.NTamd64] sections you should see a few makes and models of devices listed. You need to add the Lenovo tablet to both sections, with this line:

  • Open Windows Device Manager
  • Make sure you have enabled USB debugging in the tablet’s settings. Then, plug in the tablet via USB.
  • After a few seconds, you should see the device appear in Device Manager. Right click it and choose the option to install driver
  • Point the install driver wizard at the folder you extracted containing the Android USB driver

You will also need to download the android SDK, specifically, the Tools component. It’s probably easiest to use the Android SDK Manager to get this.

Once installed, to confirm the installation worked, open a command prompt (Start -> Run -> cmd), and run go in to the tool directory and list connected devices

it should list your tablet. If so, you can now open a shell on your tablet for the next step, with:

 Add more users

Open a command prompt, and run:

This gets you root access – you should see a popup on your tablet asking whether you want to grant super user access. Say yes to this.

Now run

It should return ‘1’. This shows that it is currently set up to only allow 1 user. You can change this by running

You’re now allowed up to 8 users. To create a new user profile, run:

You should see the new user pop up on the lock screen. Repeat the ‘create-user’ step for all the users you need.

The only problem is that the max_users setting only lasts for the current session and will be reset when you reboot the tablet. To stop this, you have to add the setting to a file called build.prop, which by default is not writeable. First exit the shell (type exit twice to drop back to the windows/linux command prompt) and take a backup of the file by doing the following:

Backup taken, back into the adb shell we go. First remount the partition writeable, then append the new setting to the end of the file: