useradd: unable to lock password file

I got the following error, when I tried to add a new user
using the adduser command

useradd: unable to lock password file

When I searched the forums, and I was able to recover from
this error by following the steps given in the following link,

http://www.thinkdigit.com/forum/open-source/61186-useradd-unable-lock-passwd-file.html

So We need to  look in your /etc/passwd ..... there should be some lock files... passwd.lock etc. Delete them,restart and get going.