In this article we will explain how to restore linux ( RHEL, CentOS , Fedora ) Password .
First please take backup from your data .
Step 1 . reboot your system and when the system want to booting heat arrow or space bar .
Step 2 . After heating arrow you will see some thing like this
Step 3 . in this step heat a on your keyboard and then you will see image below
step 4 . in this step heat space and then type 1 and inter
Step 5 . after that your system will boot as single user mode
step 6. in this step type runlevel to check if we do right or not .if the result is 1 s it means we have done well.
step 7 . in this step you can change your password by typing passwd