Resetting Ubuntu to factory settings

Solution 1:

I can see a couple of options but they depend on you being able to get to a command prompt with a working internet connection.

Install another desktop.
Burn a new USB installer from command line.

Install another desktop

This does not guarantee a working desktop though. Your problem might be something related to video card and also present in other desktops. Drop to a command line and start of with this:

sudo apt-get update

and then pick ONE of these (to install that specific desktop):

xubuntu-desktop 
lubuntu-desktop 
ubuntu-mate-desktop

I only listed a few (you could also install kUbuntu but for just getting a desktop to be able to make an installation disk might be overkill).

Burn a new USB installer from command line

Download Ubuntu from command line with

wget http://releases.ubuntu.com/14.04/ubuntu-14.04-desktop-amd64.iso

(change the url to a release you want. see http://releases.ubuntu.com and the directories below that for what you need). It will show something like this:

~/Downloads$ wget http://releases.ubuntu.com/14.04/ubuntu-14.04-desktop-amd64.iso
--2015-02-28 21:09:59--  http://releases.ubuntu.com/14.04/ubuntu-14.04-desktop-amd64.iso
Resolving releases.ubuntu.com (releases.ubuntu.com)... 
91.189.92.151, 2001:67c:1360:8c01::1e
Connecting to releases.ubuntu.com (releases.ubuntu.com)|
91.189.92.151|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1010827264 (964M) [application/x-iso9660-image]
Saving to: ‘ubuntu-14.04-desktop-amd64.iso   6%  58,05M  1,36MB/s   eta 7m 47s

and then "dd" the ISO to the USB flash drive. Pay extra attention to the device name. If you mess this up you could overwrite your current install... I tend to use dmesg:

[26005.823077] sd 7:0:0:0: Attached scsi generic sg3 type 0
[26006.953612] sd 7:0:0:0: [sdc] 30299520 512-byte logical blocks: (15.5 GB/14.4 GiB)
[26006.954291] sd 7:0:0:0: [sdc] Write Protect is off
[26006.954298] sd 7:0:0:0: [sdc] Mode Sense: 23 00 00 00
[26006.954912] sd 7:0:0:0: [sdc] No Caching mode page found
[26006.954918] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[26006.972919]  sdc: sdc1
[26006.976297] sd 7:0:0:0: [sdc] Attached SCSI removable disk

So that would be "sdc". This will burn it (skip the 1st one if you are still in Downloads, skip the 2nd one if it is already installed):

cd ~/Downloads
sudo apt-get install gddrescue
sudo ddrescue -d -D --force ubuntu-14.04-desktop-amd64.iso /dev/sdc

Results:

GNU ddrescue 1.19
Press Ctrl-C to interrupt
rescued:    63504 kB,  errsize:     230 B,  current rate:     196 kB/s
   ipos:    63504 kB,   errors:       1,    average rate:   12700 kB/s
   opos:    63504 kB, run time:       5 s,  successful read:       0 s ago
Finished

and an image of the freshly created USB ISO:

enter image description here

Solution 2:

From Factory reset - Wikipedia:

Computer factory resets will restore the computer to the computer's original operating system and delete all of the user data stored on the computer.

This can be achieved either by re-installation of the OS or using a factory reset option. But in Linux, there is no option for factory reset inbuilt. So, it is required to look for alternatives which can achieve above said things.

While re-installation of the OS is the preferred method in order to remove users, user files and user applications but it is somewhat a tedious task. There is a tool called Resetter which would make "resetting Ubuntu" easier and will do what factory resets usually do.

Introduction:

Resetter is a tool which is used to reset Ubuntu installation to factory default. The Ubuntu system will go back to the state when it was installed for the first time. It finds all applications which are installed after Ubuntu fresh installation and delete them. Not just applications, it also deletes the users too. Deleting users means deleting their home too which means all user files and configurations. You don't have to install everything from the beginning. Just reset your Ubuntu to its factory defaults and start installing everything else.

Installation:

Download the latest release of Resetter and add-apt-key_versionX.deb from GitHub or use wget to direct download. At the time of posting this answer v3.0.0 was the latest release. To download using wget use:

wget https://github.com/gaining/Resetter/releases/download/v3.0.0-stable/resetter_3.0.0-stable_all.deb
wget https://github.com/gaining/Resetter/releases/download/v3.0.0-stable/add-apt-key_1.0-0.5_all.deb

Install some dependencies:

sudo apt install libqt5clucene5 libqt5designer5 libqt5help5 python3-psutil python3-pyqt5 python3-pyqt5.qtsvg python3-sip

Install downloaded .deb packages:
```
sudo dpkg -i package1.deb package2.deb
```

Using Resetter:

Open Resetter from Dash and authenticate. Authentication is required to perform administrative tasks.
To reset Ubuntu, click on Automatic Reset. But if you want to remove multiple packages at once click on custom reset.
Click "Yes" to confirm. You'll get a dialog which would list all the packages which would be removed.
Click "OK" to start. The factory reset will begin:
A new user will be created to access the system using administrative privileges. A dialog will appear which would show details about that newly created user. After that confirmation for Reboot will appear.
If your Ubuntu boots into TTY mode (command line/console mode), login with the credentials of new user and install desktop environment again.
```
sudo apt install ubuntu-desktop
sudo reboot 
```
Use previously provided password to login.
Modify Username and Password as per convenience.