If I want to recover the password for the cisco router then I should enter to:

In rommon you'll be able to set a new password by over-writing the configuration.

 I should enter to rommon , in order to recover the router password.

Reload router and interrupt boor sequence by performing break then you are in rom monitor mode, now change register value to0X2102 and then reload router. Now copy startup to running configuration and change the password. agian change your default register value and save config. Now reload router, you can access your router.

i think by changing the registry value(2x02-2x42) in romomon mode it can be done to by pass nvram. donta forget to set back the value in config mode 

use the CTRL + Break while initializing the router to enter the ROMmon Mode   OR 

Press the MODE Button for a while after power on the router  to enter the ROMmon Mode

there u should bypass the starup Config by changing the Config Register value....

You should enter into Rommon mode to recover/reset the password

rommon is right answer to recover password for the cisco router

We must get into Rommon mode.That is from OX2102 to OX2142.Configuration entirely depend on type of router: fixed or modular.

1- Relode

2- Brock session to reach Rommon

3- Add the commend depend on Device model 

1- go to rommon

2- go to default IOS 

3- go to Start up configuration