Method 1
 
  1. Connect a terminal or PC with terminal emulation to the console port of the router and ensure you have the correct terminal settings. They include no flow control, 1 stop bit, 8 data bits, no parity and 9600 baud rate.
  2. If you are able to access the router, enter in show version at the prompt screen, and document the configuration register setting.
  3. Next, turn off the router and wait about 5 seconds and turn it back on.
  4. Press break on the terminal keyboard within 1 minute of power up in order to the router into ROMmon.
  5. Enter in confreg 0x2142 at the rommon 1> prompot in order to boot the from Flash.
  6. Type reset at the rommon 2> prompt.
  7. Type no after each setup question or press Ctrl+C to bypass all questions.
  8. Type enable at the Router> prompt
  9. Type configure memory or copy startup-config running-config in order to copy NVRAM into memory.
  10. Type show running-config
  11. Type configure terminal
  12. Type enable secret <enter in a password that you will remember> in order to change the enable secret password.
  13. Issue the no shutdown command on every single interface that you use.
  14. Type config-register . This typically is 0x2102.
  15. Press Ctrl-z or end to leave config mode.
  16. Type write memory or copy running-config startup-config to commit the modifications
 
Method 2
 
  1. Shut the router down.
  2. Remove the compact flash from the back of the router.
  3. Turn the router back on.
  4. When you see the Rommon1> prompt, enter the command of confreg 0x2142
  5. Insert the compact flash.
  6. Type reset.
  7. When prompted to enter the initial configuration, type no and press enter.
  8. At the router> prompt, type enable
  9. At the Router# prompt, enter the configure memory command, and press Enter in order to copy the startup configuration to the running configuration.
  10. Use the config t command in order to enter global configuration mode.
  11. Use this command in order to create a new user name and password:

    router(config) #username cisco privilege 15 password
    cisco
  12. Use this command in order to change the boot statement:

    config-register
    0x2102
  13. Use this command in order to save the configuration:

    write
    memory
  14. Reload the router, and then use your new user name and password to log in to the router.