How to Recover Cisco Password

For Cisco 1600,1700 and 2600 Series Routers

• Logging using console connection.
• Turn off the the router. Turn on again and press Ctrl + Break
• monitor: command "boot" aborted due to user interrupt
• rommon 1 >
• Use confreg command  to change to 2142
• rommon 1 > confreg 0x2142
• rommon 2 >
• Reboot the router using reset command. 
• rommon 2 > reset
• System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1)
• Copyright (c) 2000 by cisco Systems, Inc.
• cisco 2811 (MPC860) processor (revision 0x200) with 60416K/5120K bytes of memor
• Now go to enable mode and  copy the start up configuration to running configuration.
• Router>enable
• Router#copy startup-config running-config 
• Now remove the old password and set a new one 
• Router#configure terminal 
• Router(config)#no enable password 
• Router(config)#enable password cisco 

For Cisco 2500 Series routers use 

• Use o/r 0x2142 for confreg command and
• Use i for the reset command to reboot.