Some Password-Change related issues in ubuntu linux.Tested solutions.

Here are some Password-Change related issues in ubuntu linux and their tested solutions:

1."Authentication token manipulation error", while trying to change a Ubuntu user's password:

Possible resaon for this error is that the filesystem night be mounted as read only.  To fix it, simply type:

    mount -o remount,rw /

2. While using sudo passwd  command, it gives "password changed successfully" message., but in reality still taking the same old password, and denying the new password:

To solve this problem, first explicitly switch to the user account whose password you want to change.

    sudo su youusername

Tip: you may use sudo whoami command to find the current user.

now try :

    sudo passwd


Should work.

Unable to switch application-windows using Alt+Tab keys in Ubuntu Linux!

 If you are unable to switch application-windows such as terminal windows, gedit... using Alt+Tab keys in Ubuntu Linux, then you can try fix given below:
Go to   Dash Board > System Settings and select  Keyboard:

Select  Shortcuts tab and go to Navigation on left. Click on Switch applications setting and and set it to Alt+Tab:

 

Reboot the system.

If problem still persist, then you can try Compiz Config Settings Manager. To install  this, type:

sudo apt-get install compizconfig-settings-manager


Open it from Ubuntu Dashboard:

Go to  Window Management and check Application Switcher and Static Application Switcher:

Reboot your system, then again try Alt-Tab, it should work!!!



Tip: Compiz Config Settings Manager can help in solving many shortcut-keys related problem. For example: If show Desktop key (Alt+Control+d) is not working in your Ubuntu Linux, then you can try following steps:

Open CompizConfig Setting Manager from Ubuntu dashboard, and navigate to Key bindings  tab of General options, as shown below:

Find Show Desktop setting. It may be disabled or bounded to some keys-combination.

To set it to keys-combination of  your choice: click the Disable button: an Edit Show Desktop windows  will pop-up:

You can, select Grab key combination, and type your keys-combination. you can use default: Control Alt d. CompizConfig Setting Manager will show it as <Primary><Alt>d

Now you can toggle to Desktop by pressing keys-combination Control Alt d